func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX = (int)1e5 + 55;   const int INF = (int)1e9 + 77;   const int MOD = (int)1e9 + 7;   const double PI = 2 * acos(0.0);   const double EPS = 1e-7;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int n, m;     string s;     cin >> n >> m >> s;     for (int i = 0; i < m; ++i) {       int l, r;       char ch1, ch2;       cin >> l >> r >> ch1 >> ch2;       --l;       --r;       for (int j = l; j <= r; ++j) {         if (s[j] == ch1) s[j] = ch2;       }     }     cout << s <<   n ;     return 0;   }   