#include <bits/stdc++.h>   using namespace std;   void write(vector<int> &v) {     for (auto i : v) cout << i <<    ;     cout <<   n ;   }   void read(vector<int> &v) {     for (auto &i : v) cin >> i;   }   const int INF = 1e9;   const int64_t INFF = 1e18;   const int N = 1e6 + 69;   void solve() {     int n;     cin >> n;     string s1, s2;     cin >> s1 >> s2;     int ans = 0;     vector<int> pos(n, 1);     for (int i = 0; i < n; i++) {       if (s2[i] ==  1 ) {         if (s1[i] ==  0 ) {           ans++;           pos[i] = 0;         } else if (i > 0 && s1[i - 1] ==  1  && pos[i - 1]) {           ans++;           pos[i - 1] = 0;         } else if (i < n - 1 && s1[i + 1] ==  1  && pos[i + 1]) {           ans++;           pos[i + 1] = 0;         }       }     }     cout << ans <<   n ;   }   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int t = 1;     cin >> t;     for (int i = 1; i <= t; i++) {       solve();     }     return 0;   }   