#include <atcoder/string>
#include <bits/stdc++.h>

using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    int n, q;
    cin >> n >> q;
    string s;
    cin >> s;
    while (q--) {
        int t;
        cin >> t;
        if (t == 1) {
            int i;
            char c;
            cin >> i >> c;
            i--;
            s[i] = c;
        } else {
            string t;
            cin >> t;
            int m = t.size();
            auto v = atcoder::z_algorithm(t + s);
            bool ok = false;
            rep(i, n) {
                if (v[i + m] >= m)
                    ok = true;
            }
            cout << (ok ? "Yes" : "No") << endl;
        }
    }
    return 0;
}