func_code_string: #include <bits/stdc++.h>   using namespace std;   inline long long maxi(long long &a, long long b) {     if (b > a) {       a = b;       return 1;     }     return 0;   }   inline long long mini(long long &a, long long b) {     if (b < a) {       a = b;       return 1;     }     return 0;   }   inline long long maxi(long double &a, long double b) {     if (b > a) {       a = b;       return 1;     }     return 0;   }   inline long long mini(long double &a, long double b) {     if (b < a) {       a = b;       return 1;     }     return 0;   }   signed main() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     cout.tie(nullptr);     long long t;     cin >> t;     while (t--) {       long long n;       string a, b;       cin >> n >> a >> b;       vector<long long> ans1, ans2;       a +=  0 ;       b +=  0 ;       for (long long i = 1; i <= n; i++) {         if (a[i] != a[i - 1]) {           ans1.push_back(i);         }         if (b[i] != b[i - 1]) {           ans2.push_back(i);         }       }       for (long long i = (long long)ans2.size() - 1; i >= 0; i--) {         ans1.push_back(ans2[i]);       }       cout << (long long)ans1.size() <<   n ;       for (auto now : ans1) {         cout << now <<    ;       }       cout <<   n ;     }   }   