description: A binary string is a string that consists of characters 0 and 1. A bi-table is a table that has exactly two rows of equal length, each being a binary string.
  
  Let \operatorname{MEX} of a bi-table be the smallest digit among 0, 1, or 2 that does not occur in the bi-table. For example, \operatorname{MEX} for \begin{bmatrix} 0011\\\ 1010 \end{bmatrix} is 2, because 0 and 1 occur in the bi-table at least once. \operatorname{MEX} for \begin{bmatrix} 111\\\ 111 \end{bmatrix} is 0, because 0 and 2 do not occur in the bi-table, and 0 < 2.
  
  You are given a bi-table with n columns. You should cut it into any number of bi-tables (each consisting of consecutive columns) so that each column is in exactly one bi-table. It is possible to cut the bi-table into a single bi-table — the whole bi-table.
  
  What is the maximal sum of \operatorname{MEX} of all resulting bi-tables can be?
  
  Input
  
  The input consists of multiple test cases. The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases. Description of the test cases follows.
  
  The first line of the description of each test case contains a single integer n (1 ≤ n ≤ 10^5) — the number of columns in the bi-table.
  
  Each of the next two lines contains a binary string of length n — the rows of the bi-table.
  
  It's guaranteed that the sum of n over all test cases does not exceed 10^5.
  
  Output
  
  For each test case print a single integer — the maximal sum of \operatorname{MEX} of all bi-tables that it is possible to get by cutting the given bi-table optimally.
  
  Example
  
  Input
  
  
  4
  7
  0101000
  1101100
  5
  01100
  10101
  2
  01
  01
  6
  000000
  111111
  
  
  Output
  
  
  8
  8
  2
  12
  
  Note
  
  In the first test case you can cut the bi-table as follows:
  
    * \begin{bmatrix} 0\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 10\\\ 10 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 1\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 0.
    * \begin{bmatrix} 0\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 0\\\ 0 \end{bmatrix}, its \operatorname{MEX} is 1.
    * \begin{bmatrix} 0\\\ 0 \end{bmatrix}, its \operatorname{MEX} is 1.
  
  
  
  The sum of \operatorname{MEX} is 8.
solution: import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Random;
  import java.util.StringTokenizer;
  public class Solution{
  static FastScanner sc = new FastScanner();
  public static void solve() {
    int n=sc.nextInt();
      String s1=sc.next();
      String s2=sc.next();
      char[] c1=s1.toCharArray();
      char[] c2=s2.toCharArray();
      int i=0,ans=0;
      while (i<s1.length()) {
        if (c1[i]!=c2[i]) {
          ans+=2;
          i++;
        }else{
          if (c1[i]=='1') {
            if (i+1<s1.length() && (c1[i+1]=='0' && c2[i+1]=='0') ){
              ans+=2;
              i+=2;
            }else{
              i++;
            }
          }else{
             if (i+1<s1.length() && (c1[i+1]=='1' && c2[i+1]=='1') ){
              ans+=2;
              i+=2;
            }else{
              i++;
              ans++;
            }
          }
        }
      }
      System.out.println(ans);
    
  
    }
  
  public static void main(String[] args) {
    int t = sc.nextInt();
    outer: for (int tt = 0; tt < t; tt++) {
      solve();
    }
  }
  
  ////////////////////////////////////////////////////////////////////////////////////
  ////////////////////DO NOT READ AFTER THIS LINE //////////////////////////////////
  ////////////////////////////////////////////////////////////////////////////////////
  
  static boolean isPalindrom(char[] arr, int i, int j) {
    boolean ok = true;
    while (i <= j) {
      if (arr[i] != arr[j]) {
        ok = false;
        break;
      }
      i++;
      j--;
    }
    return ok;
  }
  
  static int max(int a, int b) {
    return Math.max(a, b);
  }
  
  static int min(int a, int b) {
    return Math.min(a, b);
  }
  
  static long max(long a, long b) {
    return Math.max(a, b);
  }
  
  static long min(long a, long b) {
    return Math.min(a, b);
  }
  
  static int abs(int a) {
    return Math.abs(a);
  }
  
  static long abs(long a) {
    return Math.abs(a);
  }
  
  static void swap(long arr[], int i, int j) {
    long temp = arr[i];
    arr[i] = arr[j];
    arr[j] = temp;
  }
  
  static void swap(int arr[], int i, int j) {
    int temp = arr[i];
    arr[i] = arr[j];
    arr[j] = temp;
  }
  
  static int maxArr(int arr[]) {
    int maxi = Integer.MIN_VALUE;
    for (int x : arr)
      maxi = max(maxi, x);
    return maxi;
  }
  
  static int minArr(int arr[]) {
    int mini = Integer.MAX_VALUE;
    for (int x : arr)
      mini = min(mini, x);
    return mini;
  }
  
  static long maxArr(long arr[]) {
    long maxi = Long.MIN_VALUE;
    for (long x : arr)
      maxi = max(maxi, x);
    return maxi;
  }
  
  static long minArr(long arr[]) {
    long mini = Long.MAX_VALUE;
    for (long x : arr)
      mini = min(mini, x);
    return mini;
  }
  
  static int gcd(int a, int b) {
    if (b == 0)
      return a;
    return gcd(b, a % b);
  }
  
  static long gcd(long a, long b) {
    if (b == 0)
      return a;
    return gcd(b, a % b);
  }
  
  static void ruffleSort(int[] a) {
    int n = a.length;
    Random r = new Random();
    for (int i = 0; i < a.length; i++) {
      int oi = r.nextInt(n);
      int temp = a[i];
      a[i] = a[oi];
      a[oi] = temp;
    }
    Arrays.sort(a);
  }
  
  public static int binarySearch(int a[], int target) {
    int left = 0;
    int right = a.length - 1;
    int mid = (left + right) / 2;
    int i = 0;
    while (left <= right) {
      if (a[mid] <= target) {
        i = mid + 1;
        left = mid + 1;
      } else {
        right = mid - 1;
      }
      mid = (left + right) / 2;
    }
    return i;
  }
  
  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());
    }
  
    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++)
        a[i] = nextInt();
      return a;
    }
  
    long[] readLongArray(int n) {
      long[] a = new long[n];
      for (int i = 0; i < n; i++)
        a[i] = nextLong();
      return a;
    }
  
    int[][] read2dArray(int n, int m) {
      int arr[][] = new int[n][m];
      for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
          arr[i][j] = nextInt();
        }
      }
      return arr;
    }
  
    ArrayList<Integer> readArrayList(int n) {
      ArrayList<Integer> arr = new ArrayList<Integer>();
      for (int i = 0; i < n; i++) {
        int a = nextInt();
        arr.add(a);
      }
      return arr;
    }
  
    long nextLong() {
      return Long.parseLong(next());
    }
  }
  
  static class pair {
    int fr, sc;
  
    pair(int fr, int sc) {
      this.fr = fr;
      this.sc = sc;
    }
  }
  
  ////////////////////////////////////////////////////////////////////////////////////  
  
  }