#include<bits/stdc++.h>
using namespace std;
const int MX = 5e5 + 7;
char str[MX];
int s[2][MX];
int P[MX],tot = 0;
int L[MX],R[MX],id[MX],ans[MX];
vector<int > querys[MX];
int lowbit(int x){return x & -x;}
void modify(int t,int x,int v){
	for(int i = x;i <= tot;i += lowbit(x))s[t][i] += v;
}
int ask(int t,int x){
	int ret = 0;
	for(int i = x;i >= 1;i -= lowbit(i))ret += s[t][i];
	return ret;
}
int query(int t,int l,int r){return ask(t,r) - ask(t,l - 1);}
int main(){
	int N,q;
	cin >> N >> q;
	cin >> str + 1;
	P[1] = 1;tot = 1;
	for(int i = 2;i <= N;i++)if(str[i] != str[i - 1])P[++tot] = i;
	P[tot + 1] = N + 1;
	for(int i = 1;i <= tot;i++)modify(0,i,P[i + 1] - P[i]);
	for(int i = 1;i <= tot;i++)modify(1,i,1);
	for(int i = 1;i <= tot;i++)id[i] = i;
	sort(id + 1,id + 1 + tot,[&](int x,int y){return P[x + 1] - P[x] < P[y + 1] - P[y];});
	for(int i = 1;i <= q;i++){
		int k;cin >> L[i] >> R[i] >> k;
		querys[k].push_back(i);
	}
	int cur = 1;
	for(int i = 0;i <= N;i++){
		while(cur <= tot && P[id[cur] + 1] - P[id[cur]] <= i){modify(0,id[cur],P[id[cur]] - P[id[cur] + 1]);modify(1,id[cur],-1);cur++;}
		for(auto it : querys[i]){
			int ll = upper_bound(P + 1,P + 1 + tot,L[it]) - P - 1,rr = upper_bound(P + 1,P + 1 + tot,R[it]) - P - 1;
			if(ll == rr)ans[it] = max(0,R[i] - L[i] + 1 - i);
			else{
				ans[it] = query(0,ll + 1,rr - 1) - i * query(1,ll + 1,rr - 1);
				ans[it] += max(0,P[ll + 1] - L[it] - i);
				ans[it] += max(0,R[it] - P[rr] + 1 - i);
			}
		}
	}
	for(int i = 1;i <= q;i++)cout << ans[i] << '\n';
	return 0;
}