#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
const int N = 500 + 3;
int n, Q;
string s;
map< pair< int, int >, int > memo;
void solve(){
cin >> n >> s >> Q;
while(Q--){
int L, R; cin >> L >> R; --L; --R;
if(memo.count({L, R})){
cout << memo[{L, R}] << '\n';
continue;
}
bool vis[n]; memset(vis, false, sizeof(vis));
int sum = 0, ans = 0;;
for(int i = L; i <= R; ++i){
int vote = (s[i] == 'C' ? +1 : -1);
if(sum + vote < 0){
vis[i] = true;
++ans;
} else {
sum += vote;
}
}
sum = 0;
for(int i = R; i >= L; --i){
if(!vis[i]){
int vote = (s[i] == 'C' ? +1 : -1);
if(sum + vote < 0){
vis[i] = true;
++ans;
} else {
sum += vote;
}
}
}
cout << ans << '\n';
memo[{L, R}] = ans;
}
}
int main(){
// #ifndef ONLINE_JUDGE
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
// #endif
ios_base::sync_with_stdio(false); cin.tie(0);
int t = 1;
// cin >> t;
for(int i = 1; i <= t; i++){
// cout << "Case #" << i << ": ";
solve();
}
return 0;
}
