#include <bits/stdc++.h>
using namespace std;
#define long long long
const long MOD = 1e9+7, LINF = 1e18 + 1e16;
const int INF = 1e9+1;
const double EPS = 1e-10;
const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
const int N = 5e5+1;
class ElectionsBruteForce {
int n, q;
string s;
public:
void run(istream &cin, ostream &cout) {
cin >> n >> s >> q;
for(int i = 0, l, r; i < q; i++) {
cin >> l >> r;
--l, --r;
vector<bool> mark(n);
int cnt = 0, curr = 0;
for(int j = l; j <= r; j++) {
if(curr + (s[j] == 'C' ? 1 : -1) < 0) {
mark[j] = true;
++cnt;
} else curr += (s[j] == 'C' ? 1 : -1);
}
curr = 0;
for(int j = r; j >= l; j--) if(!mark[j]) {
if(curr + (s[j] == 'C' ? 1 : -1) < 0) mark[j] = true, ++cnt;
else curr += (s[j] == 'C' ? 1 : -1);
}
cout << cnt << '\n';
}
}
};
class Solver {
public:
void solve(std::istream& in, std::ostream& out) {
ElectionsBruteForce *obj = new ElectionsBruteForce();
obj->run(in, out);
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
Solver solver;
std::istream& in(std::cin);
std::ostream& out(std::cout);
solver.solve(in, out);
return 0;
}
