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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll,ll>;
using vb = vector<bool>;
using vi = vector<int>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvll = vector<vll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vs = vector<string>;
using vc = vector<char>;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(a) (a).begin(), (a).end()
#define uniq(v) sort(all(v)), (v).erase(unique(all(v)),(v).end())
#define lb(v,x) int(lower_bound(all(v),(x))-(v).begin())
#define ub(v,x) int(upper_bound(all(v),(x))-(v).begin())
#define rrep(i,n) for(int i = (int)(n) - 1; i>=0; i--)
#define rep1(i,n) for(int i=1; i <=(int)(n);i++)
#define reps(i,s,n) for(int i=(int)(s);i<(int)(n); i++)
#define koz " "
#define tor "\n"
template<class T> using min_pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> bool chmin(T& a, const T& b){if(b<a){a=b;return true;}return false;}
template<class T> bool chmax(T& a, const T& b){if(a<b){a=b;return true;}return false;}
template<typename T, typename U> T ceil(T x, U y){
    assert(y!=0);
    if(y<0) x=-x,y=-y;
    return (x>0 ? (x+y-1)/y : x/y);
}
template<typename T, typename U> T floor(T x, U y){
    assert(y!=0);
    if(y<0) x=-x,y=-y;
    return (x>0 ? x/y : (x-y+1)/y);
}
template<typename T> int popcnt(T x){return __builtin_popcountll(x);}

const int dx[]={1,0,-1,0,1,1,-1,-1};
const int dy[]={0,1,0,-1,1,-1,1,-1};

const int INF = 1045141919;
const ll LINF = 3643648101145141919;
// Z[i] = S[i..] と S[0..] の最長共通接頭辞長。全体 O(n)
vi z_algorithm(const string &s){
    int n = s.size();
    vi z(n);
    z[0] = n;
    int l = 0, r = 0;
    for(int i = 1; i < n; i++){
        if(i < r) z[i] = min(r - i, z[i - l]);
        while(i + z[i] < n && s[z[i]] == s[i + z[i]]) z[i]++;
        if(i + z[i] > r){ l = i; r = i + z[i]; }
    }
    return z;
}
void solve(){
    int n,q;
    cin >> n >>q;
    string s;
    cin >> s;
    while(q--){
        int t;
        cin >> t;
        if(t==1){
            int idx;
            char c;
            cin >> idx >> c;
            idx--;
            s[idx]=c;
        }
        else{
            string t;
            cin >> t;
            string al=t+'0'+s;
            vi z=z_algorithm(al);
            int sz=t.size();
            int up=al.size();
            bool ok=false;
            reps(i,sz+1,up){
                if(z[i]==sz) ok=true;
            }
            if(ok) cout << "Yes" << tor;
            else cout << "No" << tor;

        }
    }
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(16);

    int _ = 1;
    //cin >> _;
    while(_--) solve();
    
}