#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")

#include <iostream>
using namespace std;

int N, Q;
char S[200200], a[4];

long long query(int l, int r) {
  long long ans = 0, bns = 0;
  for (int i = l; i + 2 < r; i++) {
    bool cond = S[i] == a[0] && S[i + 1] == a[1] && S[i + 2] == a[2];
    ans += cond ? i : 0;
    bns += cond ? 1 : 0;
  }
  return ans - bns * (l - 1);
}

int main() {
  cin >> N >> Q >> S;
  while (Q--) {
    int cmd;
    cin >> cmd;
    if (cmd == 1) {
      int k;
      char x;
      cin >> k >> x;
      k--;
      S[k] = x;
    } else {
      int l, r;
      cin >> l >> r >> a;
      --l;
      cout << query(l, r) << "\n";
    }
  }
}