/**
	author:  shobonvip
	created: 2025.08.16 18:04:39
**/

#include<bits/stdc++.h>
using namespace std;
#include<atcoder/fenwicktree>
typedef long long ll;
#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define all(v) v.begin(), v.end()

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n,q;
	cin>>n>>q;
	string s;
	cin>>s;
	string org=s;

	vector seg0(26*26*26,atcoder::fenwick_tree<ll>(0)); // 個数の和
	vector seg1(26*26*26,atcoder::fenwick_tree<ll>(0)); // 添字の和
	vector dat(26*26*26,vector<int>(0)); // とりうる index の集合

	auto ston = [](string s) -> int {
		return int(s[0]-'a')*26*26+int(s[1]-'a')*26+int(s[2]-'a');
	};

	rep(i,2,n){
		dat[ston(s.substr(i-2,3))].push_back(i);
	}

	vector<int> t(q),k(q),l(q),r(q);
	vector<char> c(q);
	vector<string> a(q);
	rep(i,0,q){
		cin>>t[i];
		if(t[i]==1){
			cin >> k[i] >> c[i];
			k[i]--;
			s[k[i]] = c[i];
			rep(j,max(2,k[i]),min(k[i]+3,n)){
				dat[ston(s.substr(j-2,3))].push_back(j);
			}
		}else{
			cin >> l[i] >> r[i];
			cin >> a[i];
			l[i]--;
		}
	}

	s=org;

	rep(i,0,26*26*26){
		sort(all(dat[i]));
		dat[i].erase(unique(all(dat[i])),dat[i].end());
		seg0[i] = atcoder::fenwick_tree<ll>((int)dat[i].size());
		seg1[i] = atcoder::fenwick_tree<ll>((int)dat[i].size());
	}

	auto bisect_left = [](vector<int> &dat, int i) -> int {
		return int(lower_bound(all(dat),i)-dat.begin());
	};
	
	rep(i,2,n){
		int x = ston(s.substr(i-2,3));
		int idx = bisect_left(dat[x],i);
		seg0[x].add(idx,1LL);
		seg1[x].add(idx,(ll)i);
	}

	rep(i,0,q){
		if(t[i]==1){
			rep(j,max(2,k[i]),min(k[i]+3,n)){
				int x = ston(s.substr(j-2,3));
				int idx = bisect_left(dat[x],j);
				seg0[x].add(idx,-1LL);
				seg1[x].add(idx,-(ll)j);
			}
			s[k[i]] = c[i];
			rep(j,max(2,k[i]),min(k[i]+3,n)){
				int x = ston(s.substr(j-2,3));
				int idx = bisect_left(dat[x],j);
				seg0[x].add(idx,1LL);
				seg1[x].add(idx,(ll)j);
			}
		}else{
			int x = ston(a[i]);
			if(r[i]-l[i]<=2){
				cout << 0 << '\n';
				continue;
			}
			int lb = bisect_left(dat[x],l[i]+2);
			int ub = bisect_left(dat[x],r[i]);
			ll v1 = seg1[x].sum(lb,ub);
			ll v0 = seg0[x].sum(lb,ub);
			ll ans = v1-(l[i]+1)*v0;
			cout << ans << '\n';
		}
	}
}