#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;

void solve(){
    int n,q;
    cin >> n >> q;
    string s;
    cin >> s;
    vector<set<int>> rec(26);
    rep(i,s.size()){
        char c=s[i];
        rec[c-'a'].insert(i);
    }
    while(q--){
        int tu;
        cin >> tu;
        if(tu==1){
            int idx;
            cin >> idx;
            char c;
            cin >> c;
            idx--;
            char now=s[idx];
            auto it=rec[now-'a'].lower_bound(idx);
            rec[now-'a'].erase(it);
            rec[c-'a'].insert(idx);
            s[idx]=c;
        }
        else{
            string t;
            cin >> t;
            int now=-1;
            bool ok=true;
            for(auto c:t){
                int dig=c-'a';
                auto it=rec[dig].upper_bound(now);
                if(it==rec[dig].end()){
                    ok=false;
                    break;
                }
                now=*it;
            }
            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();
    
}