#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
 
#define ALL(obj) (obj).begin(),(obj).end()
#define SPEED cin.tie(0);ios::sync_with_stdio(false);
 
template<class T> using PQ = priority_queue<T>;
template<class T> using PQR = priority_queue<T,vector<T>,greater<T>>;
 
constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433;
 
template <class T> vector<T> multivector(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto multivector(size_t N,T... t){return vector<decltype(multivector(t...))>(N,multivector(t...));}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max(a,b);}
template <class T> void chmin(T& a, const T b){a=min(a,b);}
void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;}


template<class Operator> class SegmentTree {
	Operator Op;                            //Operator 演算子、型、単位元を持つ
	using typeNode = decltype(Op.unitNode); //nodeの型
	size_t length;                          //セグメント木の最下段の要素の数(vectorの要素の数を超える2べきの数)
	vector<typeNode> node;                  //ノード

public:

	//unitで初期化
	SegmentTree(const size_t num){
		for (length = 1; length < num; length *= 2);
		node.resize(2 * length, Op.unitNode);
	}

	//vectorで初期化
	SegmentTree(const vector<typeNode> & vec){
		for (length = 1; length < vec.size(); length *= 2);
		node.resize(2 * length, Op.unitNode);
		for (int i = 0; i < vec.size(); ++i) node[i + length] = vec[i];
		for (int i = length - 1; i >= 0; --i) node[i] = Op.funcNode(node[(i<<1)+0],node[(i<<1)+1]);
	}
 
	//同じinitで初期化
	SegmentTree(const size_t num, const typeNode init) {
		for (length = 1; length < num; length *= 2);
		node.resize(2 * length, init);
	}
	
	//idx : 0-indexed
	void update(size_t idx, const typeNode var) {
		if(idx < 0 || length <= idx) return;
		idx += length;
		node[idx] = Op.funcMerge(node[idx],var);
		while(idx >>= 1) node[idx] = Op.funcNode(node[(idx<<1)+0],node[(idx<<1)+1]);
	}

	//[l,r)
	typeNode get(int l, int r) {
		if (l < 0 || length <= l || r < 0 || length < r) return Op.unitNode;
		typeNode vl = Op.unitNode, vr = Op.unitNode;
		for(l += length, r += length; l < r; l >>=1, r >>=1) {
			if(l&1) vl = Op.funcNode(vl,node[l++]);
			if(r&1) vr = Op.funcNode(node[--r],vr);
		}
		return Op.funcNode(vl,vr);
	}
 
	void print(){
		cout << "{ " << get(0,1);
		for(int i = 1; i < length; ++i) cout << ", " << get(i,i+1);
		cout << " }" << endl;

		for(int i = 1,j = 1; i < 2*length; ++i) {
			cout << node[i] << " ";
			if(i==((1<<j)-1) && ++j) cout << endl;
		}
	}

};

//一点加算 区間最大
template<class typeNode> struct nodeSumRangeMax {
	typeNode unitNode = 0;
	typeNode funcNode(typeNode l,typeNode r){return max(l,r);}
	typeNode funcMerge(typeNode l,typeNode r){return l+r;}
};

//一点加算 区間総和
template<class typeNode> struct nodeSumRangeSum {
	typeNode unitNode = 0;
	typeNode funcNode(typeNode l,typeNode r){return l+r;}
	typeNode funcMerge(typeNode l,typeNode r){return l+r;}
};

//一点更新 区間最小
template<class typeNode> struct nodeUpdateRangeMin {
	typeNode unitNode = (1LL<<31)-1;
	typeNode funcNode(typeNode l,typeNode r){return min(l,r);}
	typeNode funcMerge(typeNode l,typeNode r){return r;}
};

//一点更新 区間最小
template<class typeNode> struct nodeUpdateRangeOr {
	typeNode unitNode = 0;
	typeNode funcNode(typeNode l,typeNode r){return (l|r);}
	typeNode funcMerge(typeNode l,typeNode r){return r;}
};

//Digit Sum
long long DigitSum(long long N, long long K) {
    long long sum = 0;
    for (; N > 0; N /= K) sum += N % K;
    return sum;
}

int main() {
    int N; cin >> N;
    string S; cin >> S;
    SegmentTree<nodeUpdateRangeOr<ll>> seg(N);
    for(int i = 0; i < N; ++i){
        ll c = S[i]-'a';
        seg.update(i,1<<c);
    }
    int Q; cin >> Q;
    for(int i = 0; i < Q; ++i){
        int q; cin >> q;
        if(q==1){
            int a;
            char d;
            cin >> a >> d;
            int b = d-'a';
            a--;
            seg.update(a,1<<b);
        }
        else{
            int l,r; cin >> l >> r;
            l--;
            cout << DigitSum(seg.get(l,r),2) << endl;
        }
    }


    return 0;
}

Measured memory_bytes: 9092