func_code_string: #include <bits/stdc++.h>   using namespace std;   int N;   char s[500010];   int c[30][500010];   int then(int x) { return x & -x; }   void in(int o, int x, int k) {     while (x <= N) {       c[o][x] += k;       x += then(x);     }   }   int out(int o, int x) {     int re = 0;     while (x > 0) {       re += c[o][x];       x -= then(x);     }     return re;   }   int main() {     int Q;     scanf( %s%d , s + 1, &Q);     N = strlen(s + 1);     for (int i = 1; i <= N; i++) in(s[i] -  a , i, 1);     for (int i = 1; i <= Q; i++) {       int o;       scanf( %d , &o);       if (o == 1) {         int k;         char m;         scanf( %d %c , &k, &m);         in(s[k] -  a , k, -1);         in(m -  a , k, 1);         s[k] = m;       } else {         int x, y;         scanf( %d%d , &x, &y);         int give = 0;         for (int i = 0; i <= 25; i++)           if (out(i, y) - out(i, x - 1)) give++;         printf( %d n , give);       }     }     return 0;   }   