#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
int lg2[500005];
vector<vector<int> > stF, stB;
vector<int> P, PR;
int rmq(const vector<vector<int> >& st, int L, int R){
int j = lg2[R - L + 1];
return min(st[j][L], st[j][R - (1 << j) + 1]);
}
void solve(){
int N; string S;
cin>>N>>S;
P.assign(N + 1, 0);
PR.assign(N + 2, 0);
for(int i = 1; i <= N; i++){
P[i] = P[i - 1]+(S[i - 1] == 'C' ? 1 : -1);
}
for(int i = N; i>= 1; i--){
PR[N - i + 1] = PR[N - i] + (S[i - 1] == 'C' ? 1 : -1);
}
lg2[1] = 0;
for(int i = 2; i<= N; i++) lg2[i] = lg2[i / 2] + 1;
int K = lg2[N] + 1;
stF.assign(K, vector<int>(N + 1));
stB.assign(K, vector<int>(N + 1));
for(int i = 1; i<= N; i++){
stF[0][i] = P[i];
stB[0][i] = PR[i];
}
for(int j = 1; j < K; j++){
for(int i = 1; i + (1 << j) - 1 <= N; i++){
stF[j][i] = min(stF[j - 1][i], stF[j - 1][i + (1 << (j - 1))]);
stB[j][i] = min(stB[j - 1][i], stB[j - 1][i + (1 << (j - 1))]);
}
}
int Q;
cin>>Q;
while(Q--){
int L, R;
cin>>L>>R;
int baseF = P[L - 1];
int mnF = rmq(stF, L, R);
int delF = max(0, baseF-mnF);
int Lp = N - R + 1, Rp = N - L + 1;
int baseB = PR[Lp - 1];
int mnB = rmq(stB, Lp, Rp);
int delB = max(0, baseB - mnB);
cout<<max(delF, delB)<<"\n";
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int t = 1;
//cin>>t;
while(t--){
solve();
}
}
