#include <bits/stdc++.h>
using namespace std;

int main() {
	int N, Q;
	cin >> N >> Q;
	string S;
	cin >> S;
	
	vector s(26, set<int>{N});
	for(int i = 0; i < N; ++i) s[S[i] - 'a'].insert(i);
	
	while(Q--) {
		int cmd;
		cin >> cmd;
		
		if(cmd == 1) {
			int i; char c;
			cin >> i >> c, --i;
			
			s[S[i] - 'a'].erase(i);
			S[i] = c;
			s[S[i] - 'a'].insert(i);
		}
		
		if(cmd == 2) {
			string T;
			cin >> T;
			
			int now = 0;
			for(auto c : T) now = *s[c - 'a'].lower_bound(now);
			
			cout << (now < N ? "Yes" : "No") << "\n";
		}
	}
}