#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i,n) for (int i=0;i<(int)(n);i++)

struct S{
	vector<ll> v1,v2,v3;
	ll sm;
	S():v1(26,0),v2(26,0),sm(0){}
};
S op(S a,S b){
	S c;
	ll smb=0;
	rep(i,26){
		c.v1[i]=a.v1[i]+b.v1[i];
		c.v2[i]=a.v2[i]+b.v2[i];
		smb+=b.v1[i];
	}
	c.sm=a.sm+b.sm;
	rep(i,26){
		c.v2[i]+=a.v1[i]*(smb-b.v1[i]);
		c.sm+=a.v1[i]*b.v2[i];
		c.sm+=(a.v1[i]-1)*a.v1[i]/2*(smb-b.v1[i]);
	}
	return c;
}
S e(){
	return S();
}
S mk(char c){
	S s;
	s.v1[c-'A']++;
	return s;
}

int main(){
	int n,q;
	string s;
	cin>>n>>s>>q;
	atcoder::segtree<S,op,e> seg(n);
	rep(i,n) seg.set(i,mk(s[i]));
	rep(i,q){
		int t;
		cin>>t;
		if(t==1){
			int x;
			char c;
			cin>>x>>c;
			x--;
			seg.set(x,mk(c));
		}else{
			int l,r;
			cin>>l>>r;
			l--;
			cout<<seg.prod(l,r).sm<<"\n";
		}
	}
}