#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
typedef unsigned long long ull ;
// mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const int MAXN = 500007 ;
int n ;
string a ;
struct node {
int sm , pref , suff ;
int ans = 0 ;
node ( ) { sm = pref = suff = 0 ; }
node ( int _sm , int _pref , int _suff ) {
sm = _sm , pref = _pref , suff =_suff ;
ans = min ( pref , suff ) ;
}
};
node tr[ 4 * MAXN ] ;
node unite ( node l , node r ) {
node ret = node ( ) ;
ret.sm = l.sm + r.sm ;
ret.ans = l.pref + r.suff ;
ret.ans = min ( ret.ans , l.ans + r.sm ) ;
ret.ans = min ( ret.ans , r.ans + l.sm ) ;
ret.pref = min ( l.pref , l.sm + r.pref ) ;
ret.suff = min ( r.suff , r.sm + l.suff ) ;
return ret ;
}
void init ( int where , int IL , int IR ) {
if ( IL == IR ) {
if ( a[ IL - 1 ] == 'C' ) { tr[ where ] = node ( 1 , 0 , 0 ) ; }
else { tr[ where ] = node ( -1 , -1 , -1 ) ; }
return ;
}
int mid = ( IL + IR ) / 2 ;
init ( 2 * where , IL , mid ) ;
init ( 2 * where + 1 , mid + 1 , IR ) ;
tr[ where ] = unite ( tr[ 2 * where ] , tr[ 2 * where + 1 ] ) ;
}
node query ( int where , int IL , int IR , int CURL , int CURR ) {
if ( IL > IR || CURL > CURR ) { return node ( ) ; }
if ( IR < CURL || CURR < IL ) { return node ( ) ; }
if ( CURL <= IL && IR <= CURR ) { return tr[ where ] ; }
int mid = ( IL + IR ) / 2 ;
return unite ( query ( 2 * where , IL , mid , CURL , CURR ) , query ( 2 * where + 1 , mid + 1 , IR , CURL , CURR ) ) ;
}
void solve ( ) {
cin >> n >> a ;
init ( 1 , 1 , n ) ;
int q ; cin >> q ;
while ( q -- ) {
int l , r ; cin >> l >> r ;
node aux = query ( 1 , 1 , n , l , r ) ;
cout << -aux.ans << "\n" ;
}
}
int main ( ) {
ios_base :: sync_with_stdio ( false ) ;
cin.tie ( NULL ) ;
int t = 1 ; // cin >> t ;
while ( t -- ) { solve ( ) ; }
return 0 ;
}
