#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
using namespace std;
using ll = long long;
const int N = 5e5+5 , inf = 1e9 + 7;
const ll INF = 1e18 , mod = 1e9+7;
int t[N*4];
int t2[N*4];
int a[N] , n , q , pr[N] , sf[N];
void build(int v, int tl , int tr){
if(tl == tr){
t[v] = pr[tl];
t2[v] = sf[tl];
return;
}
int tm = (tl+tr) >> 1;
build(v*2,tl,tm);
build(v*2+1,tm+1,tr);
t[v] = min(t[v*2],t[v*2+1]);
t2[v] = min(t2[v*2],t2[v*2+1]);
}
int get(int v, int tl , int tr , int l , int r){
if(l <= tl && tr <= r) return t[v];
if(tl > r || tr < l) return inf;
int tm = (tl+tr) >> 1;
return min(get(v*2,tl,tm,l,r) , get(v*2+1,tm+1,tr,l,r));
}
int get2(int v, int tl , int tr , int l , int r){
if(l <= tl && tr <= r) return t2[v];
if(tl > r || tr < l) return inf;
int tm = (tl+tr) >> 1;
return min(get2(v*2,tl,tm,l,r) , get2(v*2+1,tm+1,tr,l,r));
}
signed main(){
ios;
file("elections");
cin >> n;
string s;
cin >> s;
s = "0"+s;
for(int i = 1; i <= n; i++){
pr[i] = pr[i-1]-(s[i] == 'T') +(s[i] == 'C');
}
for(int i = n; i >= 1; i--){
sf[i] = sf[i+1]-(s[i] == 'T') +(s[i] == 'C');
}
build(1,1,n);
cin >> q;
while(q--){
int l , r;
cin >> l >> r;
int resl = get(1,1,n,l,r)-pr[l-1];
int resr = get2(1,1,n,l,r)-sf[r+1];
if(min(resl,resr) > 0) cout << 0 << "\n";
else cout << max(abs(resl) , abs(resr)) << "\n";
}
return 0;
}
