#include <bits/stdc++.h>
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
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>;
const int N = 5e5 + 10;
int n, q;
int p[N], s[N], L[N], R[N];
char c[N];
int flag[N];
struct SegmentTree {
int st[N * 4];
int lazy[N * 4];
void push(int id, int delta) {
st[id] += delta;
lazy[id] += delta;
}
void add(int id, int L, int R, int u, int v, int delta) {
if (u > R || L > v) return;
if (u <= L && R <= v) {
push(id, delta);
return;
}
push(id * 2, lazy[id]);
push(id * 2 + 1, lazy[id]);
lazy[id] = 0;
int mid = L + R >> 1;
add(id * 2, L, mid, u, v, delta);
add(id * 2 + 1, mid + 1, R, u, v, delta);
st[id] = min(st[id * 2], st[id * 2 + 1]);
}
int get(int id, int L, int R, int u, int v) {
if (u > R || L > v) return 1e9;
if (u <= L && R <= v) return st[id];
push(id * 2, lazy[id]);
push(id * 2 + 1, lazy[id]);
lazy[id] = 0;
int mid = L + R >> 1;
return min(get(id * 2, L, mid, u, v), get(id * 2 + 1, mid + 1, R, u, v));
}
} F, B;
int ans[N];
int main() {
ios :: sync_with_stdio(0); cin.tie(0);
cin >> n;
for (int i = 1; i <= n; ++i) cin >> c[i];
for (int i = 1; i <= n; ++i) p[i] = p[i - 1] + (c[i] == 'C' ? 1 : -1);
vector <int> stk;
for (int i = n; i >= 0; --i) {
while (stk.size() && p[i] <= p[stk.back()]) {
L[stk.back()] = i;
stk.pop_back();
}
stk.push_back(i);
}
while (stk.size()) {
L[stk.back()] = -1;
stk.pop_back();
}
for (int i = 1; i <= n; ++i) F.add(1, 1, n, i, n, (c[i] == 'C' ? 1 : -1));
for (int i = 1; i <= n; ++i) B.add(1, 1, n, 1, i, (c[i] == 'C' ? 1 : -1));
cin >> q;
vector <tuple <int, int, int>> work;
for (int i = 0; i < q; ++i) {
int u, v;
cin >> u >> v;
ans[i] = - min(0, F.get(1, 1, n, u, v) - p[u - 1]);
work.push_back({u, v, i});
}
sort(work.begin(), work.end());
vector <pair <int, int>> s;
for (int i = 1; i <= n; ++i) s.push_back({L[i] + 1, i});
sort(s.begin(), s.end());
int j = 0;
for (auto [u, v, i]: work) {
while (j < s.size() && s[j].first < u) {
B.add(1, 1, n, 1, s[j].second, 1);
++j;
}
int b = (v == n ? 0 : B.get(1, 1, n, v + 1, v + 1));
ans[i] -= min(0, B.get(1, 1, n, u, v) - b);
}
for (int i = 0; i < q; ++i) cout << ans[i] << '\n';
}
