#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int N; cin >> N;
string s; cin >> s;
int Q; cin >> Q;
vector<bool> removed(N, 0);
while (Q--) {
int l, r;
cin >> l >> r;
l--;
int c = 0;
int t = 0;
int rem = 0;
for (int i = l; i < r; i++) {
if (s[i] == 'C') c++;
else t++;
if (c - t < 0) {
rem += abs(c - t);
t = c;
removed[i] = true;
}
}
c = 0; t = 0;
for (int i = r - 1; i >= l; i--) {
if (removed[i]) continue;
if (s[i] == 'C') c++;
else t++;
if (c - t < 0) {
rem += abs(c - t);
t = c;
}
}
for (int i = 0; i < N; i++) removed[i] = false;
cout << rem << '\n';
}
}
