description: You have an axis-aligned rectangle room with width W and height H, so the lower left corner is in point (0, 0) and the upper right corner is in (W, H).
  
  There is a rectangular table standing in this room. The sides of the table are parallel to the walls, the lower left corner is in (x_1, y_1), and the upper right corner in (x_2, y_2).
  
  You want to place another rectangular table in this room with width w and height h with the width of the table parallel to the width of the room.
  
  The problem is that sometimes there is not enough space to place the second table without intersecting with the first one (there are no problems with tables touching, though).
  
  You can't rotate any of the tables, but you can move the first table inside the room. 
  
  <image> Example of how you may move the first table.
  
  What is the minimum distance you should move the first table to free enough space for the second one?
  
  Input
  
  The first line contains the single integer t (1 ≤ t ≤ 5000) — the number of the test cases.
  
  The first line of each test case contains two integers W and H (1 ≤ W, H ≤ 10^8) — the width and the height of the room.
  
  The second line contains four integers x_1, y_1, x_2 and y_2 (0 ≤ x_1 < x_2 ≤ W; 0 ≤ y_1 < y_2 ≤ H) — the coordinates of the corners of the first table.
  
  The third line contains two integers w and h (1 ≤ w ≤ W; 1 ≤ h ≤ H) — the width and the height of the second table.
  
  Output
  
  For each test case, print the minimum distance you should move the first table, or -1 if there is no way to free enough space for the second table.
  
  Your answer will be considered correct if its absolute or relative error doesn't exceed 10^{-6}.
  
  Example
  
  Input
  
  
  5
  8 5
  2 1 7 4
  4 2
  5 4
  2 2 5 4
  3 3
  1 8
  0 3 1 6
  1 5
  8 1
  3 0 6 1
  5 1
  8 10
  4 5 7 8
  8 5
  
  
  Output
  
  
  1.000000000
  -1
  2.000000000
  2.000000000
  0.000000000
  
  Note
  
  The configuration of the first test case is shown in the picture. But the movement of the first table is not optimal. One of the optimal movement, for example, is to move the table by (0, -1), so the lower left corner will move from (2, 1) to (2, 0). Then you can place the second table at (0, 3)-(4, 5).
  
  In the second test case, there is no way to fit both tables in the room without intersecting.
  
  In the third test case, you can move the first table by (0, 2), so the lower left corner will move from (0, 3) to (0, 5).
solution: import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.*;
  
  
  public class Main implements Runnable {
      int n, m, k;
      static boolean use_n_tests = true;
      long mod = 1_000_000_007;
      long mod1 = 998244353L;
      Random rand = new Random();
      char[] restriction;
      int[] value;
      int[][] ab;
      Map<Long, Map<Long, Long>>[] dp;
  
      void solve(FastScanner in, PrintWriter out, int testNumber) {
          int w = in.nextInt();
          int h = in.nextInt();
          Pt p1 = new Pt();
          p1.read();
          Pt p2 = new Pt();
          p2.read();
          int w1 = in.nextInt();
          int h1 = in.nextInt();
  
          int biggestH = Math.max(p1.y, h - p2.y);
          int biggestW = Math.max(p1.x, w - p2.x);
  
          if (biggestW >= w1 || biggestH >= h1) {
              out.println(0);
              return;
          }
  
          int ans = Integer.MAX_VALUE;
          if (p2.y - p1.y + h1 <= h) {
              ans = h1 - biggestH;
          }
          if (p2.x - p1.x + w1 <= w) {
              ans = Math.min(w1 - biggestW, ans);
          }
          if (ans == Integer.MAX_VALUE) {
              ans = -1;
          }
          out.println(ans);
  
      }
  
      // ****************************** template code ***********
  
      long lcm(long a, long b) {
          return (a / gcd(a, b)) * b;
      }
  
      long gcd(long a, long b) {
          return b == 0 ? a : gcd(b, a % b);
      }
  
      class Pt {
          int x, y;
  
          boolean sameAxis(Pt b) {
              return b.x == x || b.y == y;
          }
  
          int manxDist(Pt b) {
              return Math.abs(x - b.x) + Math.abs(y - b.y);
          }
  
          void read() {
              x = in.nextInt();
              y = in.nextInt();
          }
      }
  
      void swap(Integer[] a, int i, int j) {
          Integer tmp = a[i];
          a[i] = a[j];
          a[j] = tmp;
      }
  
      void swap(List<Integer> a, int i, int j) {
          Integer tmp = a.get(i);
          a.set(i, a.get(j));
          a.set(j, tmp);
      }
  
      long manhDist(long x, long y, long x1, long y1) {
          return Math.abs(x - x1) + Math.abs(y - y1);
      }
  
      double dist(double x, double y, double x1, double y1) {
          return Math.sqrt(Math.pow(x - x1, 2.0) + Math.pow(y - y1, 2.0));
      }
  
      public static class FW {
          public static void add(long[] t, int i, long value) {
              for (; i < t.length; i |= i + 1)
                  t[i] += value;
          }
  
          public static long sum(long[] t, int i) {
              long res = 0;
              for (; i >= 0; i = (i & (i + 1)) - 1)
                  res += t[i];
              return res;
          }
  
          public static void add(long[] t, int a, int b, long value) {
              add(t, a, value);
              add(t, b + 1, -value);
          }
      }
  
      int sign(int a) {
          if (a < 0) {
              return -1;
          }
          return 1;
      }
  
      long binpow(long a, int b) {
          long res = 1;
          while (b != 0) {
              if (b % 2 == 0) {
                  b /= 2;
                  a *= a;
                  a %= mod;
              }
  
              b--;
              res *= a;
              res %= mod;
          }
          return res;
      }
  
      List<Integer> getGidits(long n) {
          List<Integer> res = new ArrayList<>();
          while (n != 0) {
              res.add((int) (n % 10L));
              n /= 10;
          }
          return res;
      }
  
      List<Integer> generatePrimes(int n) {
          List<Integer> res = new ArrayList<>();
          boolean[] sieve = new boolean[n + 1];
          for (int i = 2; i <= n; i++) {
              if (!sieve[i]) {
                  res.add(i);
              }
              if ((long) i * i <= n) {
                  for (int j = i * i; j <= n; j += i) {
                      sieve[j] = true;
                  }
              }
          }
          return res;
      }
  
      int[] ask(int l) {
          System.out.printf("? %d\n", l);
          System.out.flush();
          return in.nextArray(n);
      }
  
      static int stack_size = 1 << 29;
  
      static class Coeff {
          long mod;
          long[][] C;
          long[] fact;
          boolean cycleWay = false;
  
          Coeff(int n, long mod) {
              this.mod = mod;
              fact = new long[n + 1];
              fact[0] = 1;
              for (int i = 1; i <= n; i++) {
                  fact[i] = i;
                  fact[i] %= mod;
                  fact[i] *= fact[i - 1];
                  fact[i] %= mod;
              }
          }
  
          Coeff(int n, int m, long mod) {
              // n > m
              cycleWay = true;
              this.mod = mod;
              C = new long[n + 1][m + 1];
              for (int i = 0; i <= n; i++) {
                  for (int j = 0; j <= Math.min(i, m); j++) {
                      if (j == 0 || j == i) {
                          C[i][j] = 1;
                      } else {
                          C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
                          C[i][j] %= mod;
                      }
                  }
              }
          }
  
          public long C(int n, int m) {
              if (cycleWay) {
                  return C[n][m];
              }
              return fC(n, m);
          }
  
          private long fC(int n, int m) {
              return (fact[n] * inv(fact[n - m] * fact[m] % mod)) % mod;
          }
  
          private long inv(long r) {
              if (r == 1)
                  return 1;
              return ((mod - mod / r) * inv(mod % r)) % mod;
          }
      }
  
      class Pair {
          int first;
          long second;
  
          Pair(int f, long s) {
              first = f;
              second = s;
          }
  
          public int getFirst() {
              return first;
          }
  
          public long getSecond() {
              return second;
          }
      }
  
      class MultisetTree<T> {
          int size = 0;
  
          TreeMap<T, Integer> mp = new TreeMap<>();
  
          void add(T x) {
              mp.merge(x, 1, Integer::sum);
              size++;
          }
  
          void remove(T x) {
              if (mp.containsKey(x)) {
                  mp.merge(x, -1, Integer::sum);
                  if (mp.get(x) == 0) {
                      mp.remove(x);
                  }
                  size--;
              }
          }
  
          boolean contains(T x) {
              return mp.containsKey(x);
          }
  
          T greatest() {
              return mp.lastKey();
          }
  
          T higher(T x) {
              return mp.higherKey(x);
          }
  
          T smallest() {
              return mp.firstKey();
          }
  
          int size() {
              return size;
          }
  
          int diffSize() {
              return mp.size();
          }
      }
  
      class Multiset<T> {
          int size = 0;
  
          Map<T, Integer> mp = new HashMap<>();
  
          void add(T x) {
              mp.merge(x, 1, Integer::sum);
              size++;
          }
  
          boolean contains(T x) {
              return mp.containsKey(x);
          }
  
          void remove(T x) {
              if (mp.containsKey(x)) {
                  mp.merge(x, -1, Integer::sum);
                  if (mp.get(x) == 0) {
                      mp.remove(x);
                  }
                  size--;
              }
          }
  
          int size() {
              return size;
          }
  
          int diffSize() {
              return mp.size();
          }
      }
  
      static class Range {
          int l, r;
          int id;
  
          public int getL() {
              return l;
          }
  
          public int getR() {
              return r;
          }
  
          public Range(int l, int r, int id) {
              this.l = l;
              this.r = r;
              this.id = id;
          }
      }
  
      static class Array {
          static Range[] readRanges(int n, FastScanner in) {
              Range[] result = new Range[n];
              for (int i = 0; i < n; i++) {
                  result[i] = new Range(in.nextInt(), in.nextInt(), i);
              }
              return result;
          }
  
          static List<List<Integer>> intInit2D(int n) {
              List<List<Integer>> res = new ArrayList<>();
              for (int i = 0; i < n; i++) {
                  res.add(new ArrayList<>());
              }
              return res;
          }
  
          static boolean isSorted(Integer[] a) {
              for (int i = 0; i < a.length - 1; i++) {
                  if (a[i] > a[i + 1]) {
                      return false;
                  }
              }
              return true;
          }
  
          static public long sum(int[] a) {
              long sum = 0;
              for (int x : a) {
                  sum += x;
              }
              return sum;
          }
  
          static public long sum(long[] a) {
              long sum = 0;
              for (long x : a) {
                  sum += x;
              }
              return sum;
          }
  
          static public long sum(Integer[] a) {
              long sum = 0;
              for (int x : a) {
                  sum += x;
              }
              return sum;
          }
  
          static public int min(Integer[] a) {
              int mn = Integer.MAX_VALUE;
              for (int x : a) {
                  mn = Math.min(mn, x);
              }
              return mn;
          }
  
          static public int min(int[] a) {
              int mn = Integer.MAX_VALUE;
              for (int x : a) {
                  mn = Math.min(mn, x);
              }
              return mn;
          }
  
          static public int max(Integer[] a) {
              int mx = Integer.MIN_VALUE;
              for (int x : a) {
                  mx = Math.max(mx, x);
              }
              return mx;
          }
  
          static public int max(int[] a) {
              int mx = Integer.MIN_VALUE;
              for (int x : a) {
                  mx = Math.max(mx, x);
              }
              return mx;
          }
  
          static public int[] readint(int n, FastScanner in) {
              int[] out = new int[n];
              for (int i = 0; i < out.length; i++) {
                  out[i] = in.nextInt();
              }
              return out;
          }
      }
  
      class Graph {
          List<List<Integer>> graph;
  
          Graph(int n) {
              create(n);
          }
  
          private void create(int n) {
              List<List<Integer>> graph = new ArrayList<>();
              for (int i = 0; i < n; i++) {
                  graph.add(new ArrayList<>());
              }
              this.graph = graph;
          }
  
          void read(int m, FastScanner in) {
              for (int i = 0; i < m; i++) {
                  int v = in.nextInt() - 1;
                  int u = in.nextInt() - 1;
                  graph.get(v).add(u);
              }
          }
  
          void readBi(int m, FastScanner in) {
              for (int i = 0; i < m; i++) {
                  int v = in.nextInt() - 1;
                  int u = in.nextInt() - 1;
                  graph.get(v).add(u);
                  graph.get(u).add(v);
              }
          }
      }
  
      class FastScanner {
          BufferedReader br;
          StringTokenizer st;
  
          public FastScanner(InputStream io) {
              br = new BufferedReader(new InputStreamReader(io));
          }
  
          public String line() {
              String result = "";
              try {
                  result = br.readLine();
              } catch (IOException e) {
                  e.printStackTrace();
              }
              return result;
          }
  
          public String next() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          public char[] nextc() {
              return next().toCharArray();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
  
          public int[] nextArray(int n) {
              int[] res = new int[n];
              for (int i = 0; i < n; i++) {
                  res[i] = in.nextInt();
              }
              return res;
          }
  
          public long[] nextArrayL(int n) {
              long[] res = new long[n];
              for (int i = 0; i < n; i++) {
                  res[i] = in.nextLong();
              }
              return res;
          }
  
          public Long[] nextArrayL2(int n) {
              Long[] res = new Long[n];
              for (int i = 0; i < n; i++) {
                  res[i] = in.nextLong();
              }
              return res;
          }
  
  
          public Integer[] nextArray2(int n) {
              Integer[] res = new Integer[n];
              for (int i = 0; i < n; i++) {
                  res[i] = in.nextInt();
              }
              return res;
          }
  
          public long nextLong() {
              return Long.parseLong(next());
          }
  
      }
  
      void run_t_tests() {
          int t = in.nextInt();
          int i = 0;
          while (t-- > 0) {
              solve(in, out, i++);
          }
      }
  
      void run_one() {
          solve(in, out, -1);
      }
  
      @Override
      public void run() {
          in = new FastScanner(System.in);
          out = new PrintWriter(System.out);
          if (use_n_tests) {
              run_t_tests();
          } else {
              run_one();
          }
          out.close();
      }
  
      static FastScanner in;
      static PrintWriter out;
  
      public static void main(String[] args) throws InterruptedException {
          Thread thread = new Thread(null, new Main(), "", stack_size);
          thread.start();
          thread.join();
      }
  }