#include <bits/stdc++.h>
using namespace std;
const int N = 500005;
const int INF = 1e9;
int n, m;
string s;
int sum[N];
struct Data {
int sum, mx, cnt;
Data() { sum = mx = cnt = 0; }
};
struct SegmentTree {
struct Node {
int sum, mx;
vector<int> f;
};
Node T[N << 2];
#define mid ((l + r) >> 1)
void build(int i, int l, int r) {
sum[l - 1] = 0;
for (int j = l; j <= r; ++j) {
sum[j] = sum[j - 1] + (s[j] == 'C' ? 1 : -1);
}
T[i].sum = sum[r];
int cur = 0;
vector<int> vec;
for (int j = l - 1; j <= r; ++j) {
if (sum[j] == cur) vec.push_back(j), --cur;
}
int sz = vec.size();
T[i].f.assign(sz, 0);
for (int j = 0; j < sz; ++j) {
int mx = -INF;
int tmp = j == sz - 1 ? r : vec[j + 1] - 1;
for (int k = vec[j]; k <= tmp; ++k) {
mx = max(mx, sum[k]);
}
T[i].f[j] = mx + 1;
}
for (int j = sz - 2; j >= 0; --j) T[i].f[j] = max(T[i].f[j], T[i].f[j + 1] + 1);
int mx = 0;
for (int j = 0; j < sz; ++j) {
int tmp = j == sz - 1 ? r : vec[j + 1] - 1;
for (int k = vec[j]; k <= tmp; ++k) mx = max(mx, sum[k]);
T[i].f[j] = max(T[i].f[j], mx);
}
T[i].mx = mx;
if (l == r) return;
build(i << 1, l, mid);
build(i << 1 | 1, mid + 1, r);
}
void get(int i, int l, int r, int L, int R, Data &x) {
if (l > R || L > r) return;
if (L <= l && r <= R) {
int tmp = x.sum + 1;
int sz = T[i].f.size();
if (sz <= tmp) {
x.mx = max(x.mx, x.sum + T[i].mx), x.sum += T[i].sum; return;
}
x.mx = max(x.mx, x.sum + T[i].f[tmp]);
x.sum += T[i].sum + sz - tmp;
x.cnt += sz - tmp;
return;
}
get(i << 1, l, mid, L, R, x);
get(i << 1 | 1, mid + 1, r, L, R, x);
}
#undef mid
} IT;
int main() {
ios::sync_with_stdio(false);
cin >> n >> s, s = ' ' + s;
IT.build(1, 1, n);
cin >> m;
while (m--) {
int l, r; cin >> l >> r;
Data tmp;
IT.get(1, 1, n, l, r, tmp);
cout << tmp.cnt + tmp.mx - tmp.sum << '\n';
}
}
