#include <bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
using namespace std;
signed main() {
int n, q, x, y;
string s;
cin >> n >> s;
vector<int> a(n), pref(n);
for(int i = 0; i < n; i++) {
if(s[i] == 'C') a[i] = 1;
else a[i] = -1;
pref[i] = a[i] + (i ? pref[i - 1] : 0);
}
function<int(int,int)> sum = [&](int l, int r) {
return pref[r] - (l ? pref[l - 1] : 0);
};
cin >> q;
while(q--) {
cin >> x >> y;
x--, y--;
int kak = sum(x, y);
int l = abs(min(0LL, kak)), r = y - x + 2, mid, ans, add, cnt;
bool ok;
while(l <= r) {
mid = (l + r) / 2, ok = true;
// go through
add = 0, cnt = 0;
for(int i = x; i <= y; i++) {
if(sum(x, i) + add < 0) {
add++, cnt++;
}
if(sum(x, i) + add > kak + mid || cnt > mid) {
ok = false;
break;
}
}
if(ok) {
r = mid - 1;
ans = mid;
} else l = mid + 1;
}
cout << ans << "\n";
}
}
