description: Some number of people (this number is even) have stood in a circle. The people stand in the circle evenly. They are numbered clockwise starting from a person with the number 1. Each person is looking through the circle's center at the opposite person.
  
  <image> A sample of a circle of 6 persons. The orange arrows indicate who is looking at whom.
  
  You don't know the exact number of people standing in the circle (but this number is even, no doubt). It is known that the person with the number a is looking at the person with the number b (and vice versa, of course). What is the number associated with a person being looked at by the person with the number c? If, for the specified a, b, and c, no such circle exists, output -1.
  
  Input
  
  The first line contains one integer t (1 ≤ t ≤ 10^4) — the number of test cases. Then t test cases follow.
  
  Each test case consists of one line containing three distinct integers a, b, c (1 ≤ a,b,c ≤ 10^8).
  
  Output
  
  For each test case output in a separate line a single integer d — the number of the person being looked at by the person with the number c in a circle such that the person with the number a is looking at the person with the number b. If there are multiple solutions, print any of them. Output -1 if there's no circle meeting the given conditions.
  
  Example
  
  Input
  
  
  7
  6 2 4
  2 3 1
  2 4 10
  5 3 4
  1 3 2
  2 5 4
  4 3 2
  
  
  Output
  
  
  8
  -1
  -1
  -1
  4
  1
  -1
  
  Note
  
  In the first test case, there's a desired circle of 8 people. The person with the number 6 will look at the person with the number 2 and the person with the number 8 will look at the person with the number 4.
  
  In the second test case, there's no circle meeting the conditions. If the person with the number 2 is looking at the person with the number 3, the circle consists of 2 people because these persons are neighbors. But, in this case, they must have the numbers 1 and 2, but it doesn't meet the problem's conditions.
  
  In the third test case, the only circle with the persons with the numbers 2 and 4 looking at each other consists of 4 people. Therefore, the person with the number 10 doesn't occur in the circle.
solution: import java.io.*;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.StringTokenizer;
  
  public class TP {
  
      // constants
      static final int MOD = (int) (1e9 + 7);
      static final int IMAX = 0x7fffffff;
      static final int IMIN = 0x80000000;
      static final long LMAX = 0x7fffffffffffffffL;
      static final long LMIN = -0x8000000000000000L;
      //debug
      private static final boolean oj = System.getProperty("ONLINE_JUDGE") != null;
      public static PrintWriter out;
      public static FastReader in;
  
      public static void main(String[] args) throws IOException {
          long s = System.currentTimeMillis();
          in = new FastReader();
          out = new PrintWriter(System.out);
  //        out = new PrintWriter(new BufferedWriter(new FileWriter("whereami.out")));
          pre();
          int t = 1;
          t = ni();
          for (int i = 1; i <= t; i++) {
  //            out.print("Case #" + i + ": ");
              solve();
          }
          out.flush();
          tr(System.currentTimeMillis() - s + "ms");
      }
  
      private static void pre() {
      }
  
  
      private static void solve() {
          int a = ni(), b = ni(), c = ni();
          int diff = Math.abs(a - b);
          int n = diff * 2;
          int d = (c + diff)%n;
          if (c <= n && d <= n && a<=n && b<=n )
              out.println(d==0?n:d);
          else out.println(-1);
      }
  
      //    leetcode
      static class TreeNode {
          int val;
          TreeNode left;
          TreeNode right;
  
          TreeNode() {
          }
  
          TreeNode(int val) {
              this.val = val;
          }
  
          TreeNode(int val, TreeNode left, TreeNode right) {
              this.val = val;
              this.left = left;
              this.right = right;
          }
      }
  
      //    GFG
      static class Node {
          int data;
          Node left;
          Node right;
  
          Node(int data) {
              this.data = data;
          }
  
          Node(int data, Node left, Node right) {
              this.data = data;
              this.left = left;
              this.right = right;
          }
      }
  
      //input
      private static int ni() {
          return in.nextInt();
      }
  
      private static String ns() {
          return in.next();
      }
  
      private static int[] na(int n) {
          int[] a = new int[n];
          for (int i = 0; i < n; i++) a[i] = ni();
          return a;
      }
  
      private static long[] nal(int n) {
          long[] a = new long[n];
          for (int i = 0; i < n; i++) a[i] = nl();
          return a;
      }
  
      private static long nl() {
          return in.nextLong();
      }
  
      private static double nd() {
          return in.nextDouble();
      }
  
      private static void print(char[] a) {
          for (char x : a) out.print(x + " ");
          out.println();
      }
  
      private static void print(int[] a) {
          for (int x : a) out.print(x + " ");
          out.println();
      }
  
      private static void print(long[] a) {
          for (long x : a) out.print(x + " ");
          out.println();
      }
  
      // array util
  
      private int[][] preFixSum(int[][] a) {
          int R = a.length;
          int C = a[0].length;
          int[][] psa = new int[R][C];
          psa[0][0] = a[0][0];
          for (int i = 1; i < C; i++)
              psa[0][i] = psa[0][i - 1] + a[0][i];
          for (int i = 1; i < R; i++)
              psa[i][0] = psa[i - 1][0] + a[i][0];
          for (int i = 1; i < R; i++)
              for (int j = 1; j < C; j++)
                  psa[i][j] = psa[i - 1][j] + psa[i][j - 1] - psa[i - 1][j - 1] + a[i][j];
          return psa;
      }
  
      public static int getSum(int r1, int c1, int r2, int c2, int[][] sum) {
          r1++;
          c1++;
          r2++;
          c2++;
          return sum[r2][c2] - sum[r2][c1 - 1] - sum[r1 - 1][c2] + sum[r1 - 1][c1 - 1];
      }
  
      static void reverse(int[] a) {
          for (int i = 0, n = a.length, half = n / 2; i < half; ++i) {
              int swap = a[i];
              a[i] = a[n - i - 1];
              a[n - i - 1] = swap;
          }
      }
  
      static void reverse(long[] a) {
          for (int i = 0, n = a.length, half = n / 2; i < half; ++i) {
              long swap = a[i];
              a[i] = a[n - i - 1];
              a[n - i - 1] = swap;
          }
      }
  
      static void reverse(char[] a) {
          for (int i = 0, n = a.length, half = n / 2; i < half; ++i) {
              char swap = a[i];
              a[i] = a[n - i - 1];
              a[n - i - 1] = swap;
          }
      }
  
      static int[] copy(int[] a) {
          int[] ans = new int[a.length];
          for (int i = 0; i < a.length; ++i) ans[i] = a[i];
          return ans;
      }
  
      static long[] copy(long[] a) {
          long[] ans = new long[a.length];
          for (int i = 0; i < a.length; ++i) ans[i] = a[i];
          return ans;
      }
  
      static char[] copy(char[] a) {
          char[] ans = new char[a.length];
          for (int i = 0; i < a.length; ++i) ans[i] = a[i];
          return ans;
      }
  
      static int min(int... x) {
          if (x.length == 1) return x[0];
          if (x.length == 2) return Math.min(x[0], x[1]);
          if (x.length == 3) return Math.min(x[0], Math.min(x[1], x[2]));
          int min = x[0];
          for (int i = 1; i < x.length; ++i) if (x[i] < min) min = x[i];
          return min;
      }
  
      static long min(long... x) {
          if (x.length == 1) return x[0];
          if (x.length == 2) return Math.min(x[0], x[1]);
          if (x.length == 3) return Math.min(x[0], Math.min(x[1], x[2]));
          long min = x[0];
          for (int i = 1; i < x.length; ++i) if (x[i] < min) min = x[i];
          return min;
      }
  
      // math util
      static int max(int... x) {
          if (x.length == 1) return x[0];
          if (x.length == 2) return Math.max(x[0], x[1]);
          if (x.length == 3) return Math.max(x[0], Math.max(x[1], x[2]));
          return Arrays.stream(x).max().getAsInt();
      }
  
      static long max(long... x) {
          if (x.length == 1) return x[0];
          if (x.length == 2) return Math.max(x[0], x[1]);
          if (x.length == 3) return Math.max(x[0], Math.max(x[1], x[2]));
          long max = x[0];
          for (int i = 1; i < x.length; ++i) if (x[i] > max) max = x[i];
          return max;
      }
  
      static int pow(int a, int b) {
          if (a == 0) return 0;
          int ans = 1;
          while (b > 0) {
              if ((b & 1) > 0) ans *= a;
              a *= a;
              b >>= 1;
          }
          return ans;
      }
  
      static long pow(long a, int b) {
          if (a == 0) return 0;
          long ans = 1;
          while (b > 0) {
              if ((b & 1) > 0) ans *= a;
              a *= a;
              b >>= 1;
          }
          return ans;
      }
  
      static long power(long x, int y, int p) {
          long res = 1;
          x = x % p;
          if (x == 0) return 0;
          while (y > 0) {
              if ((y & 1) != 0)
                  res = (res * x) % p;
              y = y >> 1;
              x = (x * x) % p;
          }
          return res;
      }
  
      static long modInverse(long n, int p) {
          return power(n, p - 2, p);
      }
  
      static long modInverse(int n, int p) {
          return power(n, p - 2, p);
      }
  
      static long nCrModPFermat(int n, int r, int p) {
          if (n < r)
              return 0;
          if (r == 0)
              return 1;
          int[] fac = new int[n + 1];
          fac[0] = 1;
          for (int i = 1; i <= n; i++)
              fac[i] = fac[i - 1] * i % p;
          return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p;
      }
  
      static boolean isPrime(long n) {
          for (long i = 2; i * i <= n; i++) if (n % i == 0) return false;
          return true;
      }
  
      public static long gcd(long a, long b) {
          while (b != 0) {
              a %= b;
              long t = a;
              a = b;
              b = t;
          }
          return a;
      }
  
      private static boolean sorted(int[] a) {
          for (int i = 0; i < a.length - 1; i++) {
              if (a[i] > a[i + 1]) return false;
          }
          return true;
      }
  
      private static boolean sorted(long[] a) {
          for (int i = 0; i < a.length - 1; i++) {
              if (a[i] > a[i + 1]) return false;
          }
          return true;
      }
  
      private static boolean sorted(char[] a) {
          for (int i = 0; i < a.length - 1; i++) {
              if (a[i] > a[i + 1]) return false;
          }
          return true;
      }
  
      public static int lowerBound(int[] a, int element) {
          int low = -1, high = a.length;
          while (low < high) {
              int middle = low + (high - low) / 2;
              if (element > a[middle]) {
                  low = middle + 1;
              } else {
                  high = middle;
              }
          }
          return low;
      }
  
      static int upperBound(int[] a, int element) {
          int low = -1, high = a.length;
          while (low < high) {
              int middle = low + (high - low) / 2;
              if (a[middle] > element) {
                  high = middle;
              } else {
                  low = middle + 1;
              }
          }
          return low;
      }
  
      public static int[] facs(int n, int[] primes) {
          int[] ret = new int[9];
          int rp = 0;
          for (int p : primes) {
              if (p * p > n) break;
              int i;
              i = 0;
              while (n % p == 0) {
                  n /= p;
                  i++;
              }
              if (i > 0) ret[rp++] = p;
          }
          if (n != 1) ret[rp++] = n;
          return Arrays.copyOf(ret, rp);
      }
  
      public static int[] sieveEratosthenes(int n) {
          if (n <= 32) {
              int[] primes = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31};
              for (int i = 0; i < primes.length; i++) {
                  if (n < primes[i]) {
                      return Arrays.copyOf(primes, i);
                  }
              }
              return primes;
          }
  
          int u = n + 32;
          double lu = Math.log(u);
          int[] ret = new int[(int) (u / lu + u / lu / lu * 1.5)];
          ret[0] = 2;
          int pos = 1;
  
          int[] isnp = new int[(n + 1) / 32 / 2 + 1];
          int sup = (n + 1) / 32 / 2 + 1;
  
          int[] tprimes = {3, 5, 7, 11, 13, 17, 19, 23, 29, 31};
          for (int tp : tprimes) {
              ret[pos++] = tp;
              int[] ptn = new int[tp];
              for (int i = (tp - 3) / 2; i < tp << 5; i += tp) ptn[i >> 5] |= 1 << (i & 31);
              for (int j = 0; j < sup; j += tp) {
                  for (int i = 0; i < tp && i + j < sup; i++) {
                      isnp[j + i] |= ptn[i];
                  }
              }
          }
  
          // 3,5,7
          // 2x+3=n
          int[] magic = {
                  0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13, 31, 22, 28, 18, 26, 10, 7, 12, 21,
                  17, 9, 6, 16, 5, 15, 14
          };
          int h = n / 2;
          for (int i = 0; i < sup; i++) {
              for (int j = ~isnp[i]; j != 0; j &= j - 1) {
                  int pp = i << 5 | magic[(j & -j) * 0x076be629 >>> 27];
                  int p = 2 * pp + 3;
                  if (p > n) break;
                  ret[pos++] = p;
                  if ((long) p * p > n) continue;
                  for (int q = (p * p - 3) / 2; q <= h; q += p) isnp[q >> 5] |= 1 << q;
              }
          }
  
          return Arrays.copyOf(ret, pos);
      }
  
      private static int[][] uniqCount(int[] a) {
          int n = a.length;
          int p = 0;
          int[][] b = new int[n][];
          for (int i = 0; i < n; i++) {
              if (i == 0 || a[i] != a[i - 1]) b[p++] = new int[]{a[i], 0};
              b[p - 1][1]++;
          }
          return Arrays.copyOf(b, p);
      }
  
      private static long lcm(long a, long b) {
          return a * b / gcd(a, b);
      }
  
      public static int[][] enumPrimesAndLPF(int n) {
          int[] lpf = new int[n + 1];
          double lu = Math.log(n + 32);
  
          int tot = 0;
          int[] primes = new int[(int) ((n + 32) / lu + (n + 32) / lu / lu * 1.5)];
  
          for (int i = 2; i <= n; i++) {
              lpf[i] = i;
          }
  
          for (int p = 2, tmp; p <= n; p++) {
              if (lpf[p] == p) {
                  primes[tot++] = p;
              }
              for (int i = 0; i < tot && primes[i] <= lpf[p] && (tmp = primes[i] * p) <= n; i++) {
                  lpf[tmp] = primes[i];
              }
          }
  
          return new int[][]{Arrays.copyOf(primes, tot), lpf};
      }
  
      public static int[] enumPrimes(int n) {
          int[] lpf = new int[n + 1];
          double lu = Math.log(n + 32);
  
          int tot = 0;
          int[] primes = new int[(int) ((n + 32) / lu + (n + 32) / lu / lu * 1.5)];
  
          for (int i = 2; i <= n; i++) {
              lpf[i] = i;
          }
  
          for (int p = 2, tmp; p <= n; p++) {
              if (lpf[p] == p) {
                  primes[tot++] = p;
              }
              for (int i = 0; i < tot && primes[i] <= lpf[p] && (tmp = primes[i] * p) <= n; i++) {
                  lpf[tmp] = primes[i];
              }
          }
  
          return Arrays.copyOf(primes, tot);
      }
  
      static boolean isPrime(int n) {
          for (int i = 2; i * i <= n; i++) if (n % i == 0) return false;
          return true;
      }
  
      private static void tr(Object... o) {
          if (!oj) System.out.println(Arrays.deepToString(o));
      }
  
      public String isSubset(long[] a1, long[] a2, long n, long m) {
          HashMap<Long, Integer> a1Map = new HashMap<>();
          HashMap<Long, Integer> a2Map = new HashMap<>();
          for (long x : a1) {
              a1Map.putIfAbsent(x, 0);
              a1Map.put(x, 1 + a1Map.get(x));
          }
          for (long x : a2) {
              a2Map.putIfAbsent(x, 0);
              a2Map.put(x, 1 + a2Map.get(x));
          }
          for (Map.Entry<Long, Integer> entry : a2Map.entrySet()) {
              if (!a1Map.containsKey(entry.getKey()) || entry.getValue() > a1Map.get(entry.getKey())) {
                  return "No";
              }
          }
          return "Yes";
      }
  
      public int countOccurence(int[] arr, int n, int k) {
          HashMap<Integer, Integer> map = new HashMap<>();
          for (int x : arr) {
              map.putIfAbsent(x, 0);
              map.put(x, 1 + map.get(x));
          }
          int cnt = 0;
          for (int x : map.values()) {
              if (x >= n / k) cnt++;
          }
          return cnt;
      }
  
      private float nf() {
          return (float) in.nextDouble();
      }
  
      //reader
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader() throws FileNotFoundException {
              br = new BufferedReader(new InputStreamReader(System.in));
  //            br = new BufferedReader(new FileReader("whereami.in"));
          }
  
          String next() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
      }
  }