#include <bits/stdc++.h>
#define pb push_back
#define eb emplace_back
#define int long long
using namespace std;
const int N=5e5+5;
bool banned[N];
signed main()
{
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int n;
cin>>n;
string s;cin>>s;s='?'+s;
int q;cin>>q;
while(q--)
{
int l,r;cin>>l>>r;
int ss=0;
for(int i=l;i<=r;++i)
{
if(ss==0&&s[i]=='T') {banned[i]=1;continue;}
ss+=(s[i]=='C' ? 1:-1);
}
ss=0;
for(int i=r;i>=l;--i)
{
if(banned[i]) continue;
if(ss==0&&s[i]=='T') {banned[i]=1;continue;}
ss+=(s[i]=='C' ? 1:-1);
}
int cnt=0;
for(int i=l;i<=r;++i) {cnt+=banned[i];banned[i]=0;}
cout<<cnt<<'\n';
}
}
