#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
const int maxn = 7e4 + 7;
int n , a[maxn];
void query(int l , int r)
{
vector <int> p(maxn);
for(int i = 1; i <= n; i++) p[i] = a[i];
int sum = 0;
for(int i = l; i <= r; i++)
{
sum += p[i];
if(sum < 0)
{
p[i] = 0;
sum += 1;
}
}
sum = 0;
for(int i = r; i >= l; i--)
{
sum += p[i];
if(sum < 0)
{
p[i] = 0;
sum += 1;
}
}
int ans = 0;
for(int i = l; i <= r; i++)
{
ans += (a[i] != p[i]);
}
cout << ans << '\n';
}
void solve()
{
cin >> n;
string s; cin >> s;
s = ' ' + s;
for(int i = 1; i <= n; i++)
{
if(s[i] == 'C') a[i] = 1;
else a[i] = -1;
}
int q; cin >> q;
while(q--)
{
int l , r;
cin >> l >> r;
query(l , r);
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
return 0;
}
