/*
ID: Sho10
LANG: C++
*/
#include <bits/stdc++.h> //Andrei Alexandru a.k.a Sho10
#define ll long long int
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#define all(a) (a).begin(), (a).end()
#define sz size
#define f first
#define s second
#define pb push_back
#define er erase
#define in insert
#define mp make_pair
#define pi pair
#define rc(s) return cout<<s,0
#define endl '\n'
#define mod 1000000007
#define PI 3.14159265359
#define CODE_START ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
ll n,q,l,r;
string s,a;
int32_t main(){
CODE_START;
cin>>n;
cin>>s;
cin>>q;
while(q--){
cin>>l>>r;
l--;
r--;
ll ans=0,s1=0;
a=s;
if(a[l]=='T'){
a[l]='o';
ans++;
s1=0;
}
for(ll i=l;i<=r;i++)
{
if(a[i]=='T'){
s1--;
}else if(a[i]=='C'){
s1++;
}
if(s1<0){
ans++;
a[i]='o';
s1++;
}
}
s1=0;
if(a[r]=='T'){
a[r]='o';
ans++;
}
for(ll i=r;i>=l;i--)
{
if(a[i]=='T'){
s1--;
}else if(a[i]=='C'){
s1++;
}
if(s1<0){
ans++;
s1++;
a[i]='o';
}
}
cout<<ans;
if(q!=0){
cout<<endl;
}
}
}
