#include <bits/stdc++.h>
using namespace std;
const int N = (1 << 19);
struct node {
int s;
int l;
int r;
int d;
} tr[2 * N];
node calc(node l, node r) {
node res;
res.s = l.s + r.s;
res.l = max(l.l, l.s + r.l);
res.r = max(r.r, r.s + l.r);
res.d = max({l.s + r.d, l.d + r.s, l.l + r.r});
return res;
}
int n;
string s;
void build(int l = 0, int r = N - 1, int v = 1) {
if (l == r) {
int c = (l > n || s[l] != 'C');
tr[v].s = (c ? +1 : -1);
tr[v].l = tr[v].r = tr[v].d;
return;
}
int mid = (l + r) / 2;
build(l, mid, 2 * v);
build(mid + 1, r, 2 * v + 1);
tr[v] = calc(tr[2 * v], tr[2 * v + 1]);
}
node query(int ql, int qr, int l = 0, int r = N - 1, int v = 1) {
if (r < ql || l > qr)
return node();
if (ql <= l && r <= qr)
return tr[v];
int mid = (l + r) / 2;
return calc(query(ql, qr, l, mid, 2 * v), query(ql, qr, mid + 1, r, 2 * v + 1));
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
cin >> s;
build();
int q;
cin >> q;
while (q--) {
int l, r;
cin >> l >> r;
l--, r--;
node t = query(l, r);
cout << t.d << '\n';
}
}
