#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
typedef long double ld;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll n,q;
cin >> n;
string a;
cin >> a;
cin >> q;
for (int z=0;z<q;z++){
ll l,r;
cin >> l >> r;
l--;r--;
ll c = 0;
ll t = 0;
vector <bool> arr(n,false);
for (int x=l;x<=r;x++){
if (a[x] == 'C'){
c++;
} else {
t++;
}
if (t > c){
t--;
arr[x] = true;
}
}
c = 0;
t = 0;
for (int x=r;x>=l;x--){
if (a[x] == 'C'){
c++;
} else if (!arr[x]){
t++;
}
if (t > c){
t--;
arr[x] = true;
}
}
ll ans = 0;
for (int z=0;z<n;z++){
if (arr[z]) ans++;
}
cout << ans << endl;
}
}
