#include <bits/stdc++.h>
signed main() {
int n;
std::cin >> n;
std::string c;
std::cin >> c;
std::vector<char> a(n + 1);
for(int i = 1; i <= n; i++) {
a[i] = c[i - 1];
}
int q;
std::cin >> q;
while(q--) {
int l, r;
std::cin >> l >> r;
int pref = 0;
std::vector<int> was(n + 1);
int ans = 0;
for(int i = l; i <= r; i++) {
pref += (a[i] == 'C' ? 1 : - 1);
if(pref < 0) {
was[i] = 1;
ans += 1;
pref += 1;
}
}
pref = 0;
for(int i = r; i >= l; i--) {
if(was[i]) {
continue;
}
pref += (a[i] == 'C' ? 1 : - 1);
if(pref < 0) {
was[i] = 1;
ans += 1;
pref += 1;
}
}
std::cout << ans << "\n";
}
}
