// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(x) sort(all((x))); (x).resize(unique(all((x))) - (x).begin())
typedef long long ll;
typedef long double ld;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void solve() {
int n, q;
cin >> n;
string s; cin >> s;
cin >> q;
while(q--) {
vector<int> done(n);
int l, r;
cin >> l >> r; l--; r--;
int pref = 0;
int ans = 0;
for(int i = l; i <= r; i++) {
if(s[i] == 'C') pref++;
else {
if(!pref) { done[i] = 1; ans++; }
else pref--;
}
}
int mn_pref = 0; pref = 0;
for(int i = r; i >= l; i--)
if(!done[i]) {
if(s[i] == 'C') pref++;
else {
pref--;
mn_pref = min(mn_pref, pref);
}
}
cout << ans - mn_pref << '\n';
}
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
int t = 1;
// cin >> t;
while(t--) solve();
return 0;
}
/*
*/
