description: There is a chessboard of size n by n. The square in the i-th row from top and j-th column from the left is labelled (i,j).
  
  Currently, Gregor has some pawns in the n-th row. There are also enemy pawns in the 1-st row. On one turn, Gregor moves one of his pawns. A pawn can move one square up (from (i,j) to (i-1,j)) if there is no pawn in the destination square. Additionally, a pawn can move one square diagonally up (from (i,j) to either (i-1,j-1) or (i-1,j+1)) if and only if there is an enemy pawn in that square. The enemy pawn is also removed.
  
  Gregor wants to know what is the maximum number of his pawns that can reach row 1?
  
  Note that only Gregor takes turns in this game, and the enemy pawns never move. Also, when Gregor's pawn reaches row 1, it is stuck and cannot make any further moves.
  
  Input
  
  The first line of the input contains one integer t (1≤ t≤ 2⋅ 10^4) — the number of test cases. Then t test cases follow.
  
  Each test case consists of three lines. The first line contains a single integer n (2≤ n≤ 2⋅{10}^{5}) — the size of the chessboard.
  
  The second line consists of a string of binary digits of length n, where a 1 in the i-th position corresponds to an enemy pawn in the i-th cell from the left, and 0 corresponds to an empty cell.
  
  The third line consists of a string of binary digits of length n, where a 1 in the i-th position corresponds to a Gregor's pawn in the i-th cell from the left, and 0 corresponds to an empty cell.
  
  It is guaranteed that the sum of n across all test cases is less than 2⋅{10}^{5}.
  
  Output
  
  For each test case, print one integer: the maximum number of Gregor's pawns which can reach the 1-st row.
  
  Example
  
  Input
  
  
  4
  3
  000
  111
  4
  1111
  1111
  3
  010
  010
  5
  11001
  00000
  
  
  Output
  
  
  3
  4
  0
  0
  
  Note
  
  In the first example, Gregor can simply advance all 3 of his pawns forward. Thus, the answer is 3.
  
  In the second example, Gregor can guarantee that all 4 of his pawns reach the enemy row, by following the colored paths as demonstrated in the diagram below. Remember, only Gregor takes turns in this "game"!
  
  <image>
  
  In the third example, Gregor's only pawn is stuck behind the enemy pawn, and cannot reach the end.
  
  In the fourth example, Gregor has no pawns, so the answer is clearly 0.
solution: //------------------>>>>>>>>>>>>>>>> HI . HOW ARE YOU? <<<<<<<<<<<<<<<<<<<<<<<<<<<<<------------------------------
  
  import java.io.*;
  import java.util.*;
  import java.util.List;
  import java.util.StringTokenizer;
  
  //---------------------------->>>>>>>>>>>>>>>>>>>>>> FK OFF <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<-------------------
  
  //--------------------------->>>>>>>>>>>>>>>>>>>>>>>> HACKER MF <<<<<<<<<<<<-------------------------------------
  
  public class practice{
  
      static int[] count,count1,count2;
      static boolean[] prime;
      static boolean flag;
      static int[] spf;
      static Node[] nodes,nodes1,nodes2;
      static long[] arr;
      static long[][] cost;
      static int[] arrInt,darrInt,farrInt;
      static int[][] dp;
      static char[] ch,ch1,ch2;
      static long[] darr,farr;
      static long[][] mat,mat1;
      static boolean[] vis;
      static long x,h;
      static long maxl,sum,total;
      static double dec;
      static long mx = (long)1e7;
      static long inf = (long)1e17;
      static String s,s1,s2,s3,s4;
      static long minl;
      static long mod = (long)(1e9)+7;
      // static int minl = -1;
      // static long n;
      static int n,n1,n2,q,r1,c1,r2,c2;
      static int arr_size = (int)2e5+10;
      static long a;
      static long b;
      static long c;
      static long d;
      static long y,z;
      static int m,m1;
      static long ans;
      static long k;
      static FastScanner sc;
      static String[] str,str1;
      static Set<Long> set,set1,set2;
      static SortedSet<Long> ss;
      static List<StringBuilder> list,list1,list2,list3;
      static PriorityQueue<Node> pq,pq1;
      static LinkedList<Node> ll,ll1,ll2;
      static Map<Integer,List<Integer>> map;
      static Map<Integer,Integer> map2;
      static Map<Integer,Long> mapL,mapR;
      static Map<Integer,Node> map1;
      static StringBuilder sb,sb1,sb2;
      static int index;
      static int[] dx = {0,-1,0,1,-1,1,-1,1};
      static int[] dy = {-1,0,1,0,-1,-1,1,1};
  
      static class Node{
          long first;
          int second;
          Node(long f,int s){
              this.first = f;
              this.second = s;
          }
      }
  
      static LNode head = null;
      static LNode tail = null;
  
      static class LNode{
          long key;
          long val;
          LNode next;
          LNode prev;
          LNode(long key,long val){
              this.key = key;
              this.val = val;
              this.next = null;
              this.prev = null;
          }
          LNode(long val){
              this.key = -1;
              this.val = val;
              this.next = null;
              this.prev = null;
          }
      }
  
  
  //     public static void solve(){
  //
  //        FastScanner sc = new FastScanner();
  //        int t = sc.nextInt();
  //        // int t = 1;
  //        for(int tt = 1 ; tt <= t ; tt++){
  //
  //            System.out.println("Case #"+tt+": "+ ans);
  //
  //        }
  //
  //     }
  
      //--------------->>>>IF YOU ARE HERE FOR QUICKSORT HACK THEN SORRY NO HACK FOR YOU<<<-------------------------------
  
      public static void solve(){
          char[] arr = sc.next().toCharArray();
          char[] darr = sc.next().toCharArray();
          long ans = 0;
          for(int i = 0 ; i < n ; i++){
              if(darr[i] == '0')
                  continue;
              if(arr[i] == '0') {
                  ans += 1;
                  continue;
              }
              if(i-1 >= 0 && arr[i-1] == '1') {
                  ans += 1;
                  arr[i-1] = 3;
              }
              else if(i+1 < n && arr[i+1] == '1'){
                  ans += 1;
                  arr[i+1] = 3;
              }
          }
  
          sb.append(ans).append("\n");
  
      }
  
      //----------->>>>>>> SPEED UP SPEED UP . THIS IS SPEEDFORCES . SPEED UP SPEEEEEEEEEEEEEEEEEEEEEEEEEEDDDDDD <<<<<<<------------------
  
      public static void main(String[] args) {
  
          sc = new FastScanner();
          // Scanner sc = new Scanner(System.in);
          sb = new StringBuilder();
          int t = sc.nextInt();
  //        int t = 1;
          while(t > 0){
  
  //             k = sc.nextLong();
              // x = sc.nextLong();
              // y = sc.nextLong();
              // z = sc.nextLong();
  
  //            a = sc.nextLong();
  //             b = sc.nextLong();
  //             c = sc.nextLong();
  //             d = sc.nextLong();
  //
  //             x = sc.nextLong();
  //             y = sc.nextLong();
  //             z = sc.nextLong();
              // d = sc.nextLong();
  
              n = sc.nextInt();
  
              // n1 = sc.nextInt();
  
  //            m = sc.nextInt();
  //             q = sc.nextInt();
  
  //             a = sc.nextLong();
  //             b = sc.nextLong();
  
  //             k = sc.nextLong();
  
  //            x = sc.nextLong();
              // d = sc.nextLong();
  
  //            s = sc.next();
  
  //            ch = sc.next().toCharArray();
  //            ch1 = sc.next().toCharArray();
  
  //             m = sc.nextInt();
              // n = 6;
  
  //            arr = new long[n];
  //            for(int i = 0 ; i < n ; i++){
  //                arr[i] = sc.nextLong();
  //            }
  
  //            arrInt = new int[n];
  //            for(int i = 0 ; i < n ; i++){
  //                arrInt[i] = sc.nextInt();
  //            }
  
              // x = sc.nextLong();
              // y = sc.nextLong();
  //             ch = sc.next().toCharArray();
  //            m = n;
  ////             m = sc.nextInt();
  //            darr = new long[n];
  //            for(int i = 0 ; i < n ; i++){
  //                darr[i] = sc.nextLong();
  //            }
              // k = sc.nextLong();
              // m = n;
  //             darrInt = new int[n];
  //             for(int i = 0 ; i < n ; i++){
  //                 darrInt[i] = sc.nextInt();
  //             }
  
  //             farr = new long[n];
  //             for(int i = 0 ; i < n ; i++){
  //                 farr[i] = sc.nextLong();
  //             }
  
              // farrInt = new int[m];
              // for(int i = 0; i < m ; i++){
              //     farrInt[i] = sc.nextInt();
              // }
  
              // m = n;
  //            mat = new long[n][m];
  //            for(int i = 0 ; i < n ; i++){
  //                for(int j = 0 ; j < m ; j++){
  //                    mat[i][j] = sc.nextLong();
  //                }
  //            }
  
  //             m = n;
  //             mat = new char[n][m];
  //             for(int i = 0 ; i < n ; i++){
  //                 String s = sc.next();
  //                 for(int j = 0 ; j < m ; j++){
  //                     mat[i][j] = s.charAt(j);
  //                 }
  //             }
  //
  //             str = new String[n];
  //             for(int i = 0 ; i < n ; i++)
  //                 str[i] = sc.next();
  
  //             nodes = new Node[n];
  //             for(int i = 0 ; i < n ;i++)
  //                 nodes[i] = new Node(sc.nextLong(),(i));
  
              solve();
              t -= 1;
          }
          System.out.print(sb);
  
      }
  
      public static int log(double n,double base){
  
          if(n == 0 || n == 1)
              return 0;
  
          if(n == base)
              return 1;
  
          double num = Math.log(n);
          double den = Math.log(base);
  
          if(den == 0)
              return 0;
  
          return (int)(num/den);
      }
  
      public static boolean isPrime(long n) {
          // Corner cases
          if (n <= 1)
              return false;
  
          if (n <= 3)
              return true;
  
          // This is checked so that we can skip
          // middle five numbers in below loop
          if (n%2 == 0 || n%3 == 0)
              return false;
  
          for (int i=5; i*i<=n; i=i+6)
              if (n%i == 0 || n%(i+2) == 0)
                  return false;
  
          return true;
      }
  
      public static void SpecialSieve(int MAXN)
      {
          spf = new int[MAXN];
          spf[1] = 1;
          for (int i=2; i<MAXN; i++)
  
              // marking smallest prime factor for every
              // number to be itself.
              spf[i] = i;
  
          // separately marking spf for every even
          // number as 2
          for (int i=4; i<MAXN; i+=2)
              spf[i] = 2;
  
          for (int i=3; i*i<MAXN; i++)
          {
              // checking if i is prime
              if (spf[i] == i)
              {
                  // marking SPF for all numbers divisible by i
                  for (int j=i*i; j<MAXN; j+=i)
  
                      // marking spf[j] if it is not
                      // previously marked
                      if (spf[j]==j)
                          spf[j] = i;
              }
          }
      }
  
      public static ArrayList<Integer> getFactorization(int x)
      {
          ArrayList<Integer> ret = new ArrayList<Integer>();
          while (x != 1)
          {
              ret.add(spf[x]);
              x = x / spf[x];
          }
          return ret;
      }
  
      public static long gcd(long a, long b)
      {
          if (b == 0)
              return a;
          return gcd(b, a % b);
      }
  
      public static long lcm(long a, long b)
      {
          return (b/gcd(b, a % b)) * a;
      }
  
      public static long mod_inverse(long a,long mod){
          long x1=1,x2=0;
          long p=mod,q,t;
          while(a%p!=0){
              q = a/p;
              t = x1-q*x2;
              x1=x2; x2=t;
              t=a%p;
              a=p; p=t;
          }
          return x2<0 ? x2+mod : x2;
      }
  
      public static void swap(double[] curr,int i,int j){
          double temp = curr[j];
          curr[j] = curr[i];
          curr[i] = temp;
      }
  
      static final Random random=new Random();
  
      static void ruffleSortLong(long[] a) {
          int n=a.length;//shuffle, then sort
          for (int i=0; i<n; i++) {
              int oi=random.nextInt(n);
              long temp=a[oi];
              a[oi]=a[i]; a[i]=temp;
          }
          Arrays.sort(a);
      }
  
      static void ruffleSortInt(int[] a) {
          int n=a.length;//shuffle, then sort
          for (int i=0; i<n; i++) {
              int oi=random.nextInt(n);
              int temp=a[oi];
              a[oi]=a[i]; a[i]=temp;
          }
          Arrays.sort(a);
      }
  
      static void ruffleSortChar(char[] a) {
          int n=a.length;//shuffle, then sort
          for (int i=0; i<n; i++) {
              int oi=random.nextInt(n);
              char temp=a[oi];
              a[oi]=a[i]; a[i]=temp;
          }
          Arrays.sort(a);
      }
  
      static long binomialCoeff(long n, long k){
  
          long res = 1;
  
          // Since C(n, k) = C(n, n-k)
          if (k > n - k)
              k = n - k;
  
          // Calculate value of
          // [n * (n-1) *---* (n-k+1)] / [k * (k-1) *----* 1]
          for (long i = 0; i < k; ++i) {
              res = (res*(n - i));
              res = (res/(i + 1));
          }
  
          return res;
      }
  
      static long mod(long x)
      {
          long y = mod;
          long result = x % y;
          while (result < 0)
          {
              result += y;
          }
          return result;
      }
  
      static long[] fact;
  
      public static long inv(long n){
          return power(n, mod-2);
      }
  
      public static void fact(int n){
          fact = new long[n+1];
          fact[0] = 1;
          for(int j = 1;j<=n;j++)
              fact[j] = (fact[j-1]*(long)j)%mod;
      }
  
      public static long binom(int n, int k){
  
          long prod = fact[n];
          prod*=inv(fact[n-k]);
          prod%=mod;
          prod*=inv(fact[k]);
          prod%=mod;
          return prod;
      }
  
      static long power(long x, long y){
          if (y == 0)
              return 1;
          if (y%2 == 1)
              return (x*power(x, y-1))%mod;
          return power((x*x)%mod, y/2)%mod;
      }
  
      static void sieve(int n){
  
          prime = new boolean[n+1];
          for(int i=2;i<n;i++)
              prime[i] = true;
  
          for(int p = 2; p*p <=n; p++)
          {
              if(prime[p])
              {
                  for(int i = p*p; i <= n; i += p)
                      prime[i] = false;
              }
          }
  
      }
  
      static long abs(long a){
          return Math.abs(a);
      }
  
      static int abs(int a){
          return Math.abs(a);
      }
  
      static int max(int a,int b){
          if(a>b)
              return a;
          else
              return b;
      }
      static double max(double a,double b){
          if(a>b)
              return a;
          else
              return b;
      }
      static double min(double a,double b){
          if(a>b)
              return b;
          else
              return a;
      }
  
      static int min(int a,int b){
          if(a>b)
              return b;
          else
              return a;
      }
  
      static long max(long a,long b){
          if(a>b)
              return a;
          else
              return b;
      }
  
      static long min(long a,long b){
          if(a>b)
              return b;
          else
              return a;
      }
  
      static long sq(long num){
          return num*num;
      }
  
      static double sq(double num){
          return num*num;
      }
  
      static long sqrt(long num){
          return (long)Math.sqrt(num);
      }
  
      static double sqrt(double num){
          return Math.sqrt(num);
      }
  
      static private void removeNode(LNode n){
          if(n.prev!=null){
              n.prev.next = n.next;
          }else{
              head = n.next;
          }
  
          if(n.next!=null){
              n.next.prev = n.prev;
          }else{
              tail = n.prev;
          }
      }
  
      static private void offerNode(LNode n){
  
          if(tail!=null){
              tail.next = n;
          }
  
          n.prev = tail;
          n.next = null;
          tail = n;
  
          if(head == null){
              head = tail;
          }
      }
  
      static class FastScanner {
  
          BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st=new StringTokenizer("");
          String next() {
              while (!st.hasMoreTokens())
                  try {
                      st=new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
          //        void readArray(int n) {
  //            arr = new long[n];
  //            for (int i = 0; i < n; i++)
  //                arr[i] = nextLong();
  //        }
          long nextLong() {
              return Long.parseLong(next());
          }
      }
  
  }