#include <bits/stdc++.h>
using namespace std;
int rmqst[500001][19],rmqdr[500002][19];
int sumst[500001],sumdr[500002];
char s[500001];
int logue[500001];
int queryst(int a,int b)
{
int lg=logue[b-a+1];
return min(sumst[rmqst[b][lg]],sumst[rmqst[a+(1<<lg)-1][lg]]);
}
int querydr(int a,int b)
{
int lg=logue[b-a+1];
return min(sumdr[rmqdr[b][lg]],sumdr[rmqdr[a+(1<<lg)-1][lg]]);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n,i,j,q,a,b;
cin>>n>>ws>>(s+1)>>ws;
for(i=2;i<=n;i++)
logue[i]=logue[i/2]+1;
for(i=1;i<=n;i++)
{
sumst[i]=sumst[i-1]+(s[i]=='C')-(s[i]=='T');
rmqst[i][0]=i;
}
for(i=n;i>=1;i--)
{
sumdr[i]=sumdr[i+1]+(s[i]=='C')-(s[i]=='T');
rmqdr[i][0]=i;
}
for(j=1;j<=logue[n];j++)
for(i=(1<<j);i<=n;i++)
{
if(sumst[rmqst[i][j-1]]<sumst[rmqst[i-(1<<(j-1))][j-1]])
rmqst[i][j]=rmqst[i][j-1];
else
rmqst[i][j]=rmqst[i-(1<<(j-1))][j-1];
if(sumdr[rmqdr[i][j-1]]<sumdr[rmqdr[i-(1<<(j-1))][j-1]])
rmqdr[i][j]=rmqdr[i][j-1];
else
rmqdr[i][j]=rmqdr[i-(1<<(j-1))][j-1];
}
cin>>q;
for(i=1;i<=q;i++)
{
cin>>a>>b;
cout<<max(max(-(queryst(a,b)-sumst[a-1]),-(querydr(a,b)-sumdr[b+1])),0)<<'\n';
}
return 0;
}
