#include<iostream>
#include<vector>
#include<set>
#include<algorithm>
#include<map>
#include<queue>
#include<stack>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
vll arr;
struct Node {
ll l, r;
Node* lp, * rp;
ll sum_intreval = 0, min_suf = 0;
Node(ll L, ll R) {
l = L, r = R;
if (l + 1 == r) {
sum_intreval = arr[l];
min_suf = arr[l];
return;
}
lp = new Node(l, (l + r) / 2);
rp = new Node((l + r) / 2, r);
pull();
}
void pull() {
sum_intreval = lp->sum_intreval + rp->sum_intreval;
min_suf = min(rp->min_suf, rp->sum_intreval + lp->min_suf);
}
void update(ll start, ll x) {
if (start < l || start >= r) { return; }
if (start == l && start + 1 == r) {
sum_intreval = x;
min_suf = x;
return;
}
lp->update(start, x);
rp->update(start, x);
pull();
}
ll solve(ll start, ll end, ll& sum_to_now) {
if (start >= r || end <= l) { return 1e18; }
if (start <= l && r <= end) {
sum_to_now += sum_intreval;
return sum_to_now + min_suf - sum_intreval;
}
ll ans = 1e18;
ans = min(ans, rp->solve(start, end, sum_to_now));
ans = min(ans, lp->solve(start, end, sum_to_now));
return ans;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
ll n;
cin >> n;
string s;
cin >> s;
arr.resize(n);
for (ll i = 0; i < n; i++) {
if (s[i] == 'C') {
arr[i] = 1;
}
else {
arr[i] = -1;
}
}
ll q;
cin >> q;
vector<vpll> quries(n);
for (ll i = 0; i < q; i++) {
ll l, r;
cin >> l >> r;
l--, r--;
quries[l].push_back({ r, i });
}
Node* root = new Node(0, n);
vll index;
vll ans(q);
for (ll i = n - 1; i >= 0; i--) {
if (arr[i] == 1) {
if (!index.empty()) {
root->update(index.back(), -1);
index.pop_back();
}
}
else {
index.push_back(i);
root->update(i, 0);
}
ll sum_to_now = 0;
for (auto j : quries[i]) {
sum_to_now = 0;
ans[j.second] -= min(root->solve(i, j.first + 1, sum_to_now), ll(0));
ans[j.second] += index.end() - lower_bound(index.begin(), index.end(), j.first, greater<ll>());
}
}
for (ll i = 0; i < q; i++) {
cout << ans[i] << '\n';
}
}
