#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;
    vector<set<int>> st(26);
    string s;
    cin >> s;
    rep(i, n) {
        st[s[i] - 'a'].insert(i);
    }
    while (q--) {
        int t;
        cin >> t;
        if (t == 1) {
            int i;
            char c;
            cin >> i >> c;
            i--;
            st[s[i] - 'a'].erase(i);
            s[i] = c;
            st[s[i] - 'a'].insert(i);
        } else {
            bool ok = true;
            string t;
            cin >> t;
            int cur = -1;
            for (char c : t) {
                int d = c - 'a';
                auto it = st[d].upper_bound(cur);
                if (it == st[d].end()) {
                    ok = false;
                } else {
                    cur = *it;
                }
            }
            cout << (ok ? "Yes" : "No") << endl;
        }
    }

    return 0;
}