#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e3 + 100;
int a[maxn];
bool u[maxn];
int main()
{
int n;
cin >> n;
for (int i = 1;i <= n;i++)
{
char inp;
cin >> inp;
a[i] = (inp == 'C') * 2 - 1;
}
int q;
cin >> q;
while (q--)
{
int l, r;
cin >> l >> r;
int ans = 0, s = 0;
for (int i = l;i <= r;i++)
{
s += a[i];
if (s < 0)
{
s++;
ans++;
u[i] = 1;
}
}
s = 0;
for (int i = r;i >= l;i--)
{
if (!u[i])
{
s += a[i];
}
if (s < 0)
{
s++;
ans++;
}
}
for (int i = l;i <= r;i++)
{
u[i] = 0;
}
cout << ans << '\n';
}
}
