#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/modint>
// using namespace atcoder;
// using mint = modint998244353;
using ll = long long;
#define fix(x) fixed << setprecision(x)
#define rep(i, n) for(int i = 0; i < n; ++i)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int enc(string s){
    assert(s.size()==3);
    int res = 0, t = 1;
    rep(i,3) res += (s[i]-'a') * t, t *= 26;
    return res;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,q;
    cin >> n >> q;
    string s;
    cin >> s;
    int log = 0;
    while(n-2>(1<<log)) ++log;
    vector<map<int,ll>> seg(17576);
    rep(i,n-2){
        int x = enc(s.substr(i,3)), idx = i+(1<<log);
        while(idx) seg[x][idx] += ((ll)(i+1)<<18) + 1, idx >>= 1;
    }
    while(q--){
        int t;
        cin >> t;
        if(t==1){
            int k; char c;
            cin >> k >> c;
            --k;
            for(int i=max(k-2,0);i<min(k+1,n-2);++i){
                int x = enc(s.substr(i,3)), idx = i+(1<<log);
                while(idx) seg[x][idx] -= ((ll)(i+1)<<18) + 1, idx >>= 1;
            }
            s[k] = c;
            for(int i=max(k-2,0);i<min(k+1,n-2);++i){
                int x = enc(s.substr(i,3)), idx = i+(1<<log);
                while(idx) seg[x][idx] += ((ll)(i+1)<<18) + 1, idx >>= 1;
            }
        }else{
            int l,r,z;
            string t;
            cin >> l >> r >> t;
            --l;
            z = l;
            r -= 2;
            if(l>r){
                cout << "0\n";
                continue;
            }
            l += 1<<log, r += 1<<log;
            int x = enc(t);
            ll tot = 0;
            while(l<r){
                if(l&1) tot += seg[x][l++];
                if(r&1) tot += seg[x][--r];
                l >>= 1, r >>= 1;
            }
            ll cnt = tot & ((1<<18)-1);
            tot >>= 18;
            cout << tot-z*cnt << '\n';
        }
    }
    return 0;
}