#include <bits/stdc++.h>
using namespace std;
const int N = (1 << 19);
struct node {
int pre;
int mid;
int suf;
} tr[2 * N];
node calc(node l, node r) {
if (!l.mid) {
r.pre += l.pre;
if (!r.mid) r.suf += l.suf;
return r;
}
if (!r.mid) {
l.suf += r.suf;
return l;
}
int A = l.mid;
int B = l.suf + r.pre;
int C = r.mid;
int k = min({A, B, C});
A -= k, B -= k, C -= k;
node res;
res.pre = l.pre + (!A) * B + (!A && !C) * r.suf;
res.mid = A + C;
res.suf = r.suf + (!C) * B + (!C && !A) * l.pre;
return res;
}
int n;
string s;
void build(int l = 0, int r = N - 1, int v = 1) {
if (l == r) {
bool c = (l > n || s[l] != 'C');
tr[v].pre = c;
tr[v].suf = c;
tr[v].mid = !c;
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;
s = '#' + s;
build();
int q;
cin >> q;
while (q--) {
int l, r;
cin >> l >> r;
node t = query(l, r);
cout << t.pre + (t.mid > 0) * t.suf << '\n';
}
}
