#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 1e9 + 7;
const ll mod2 = 998244353;
ll gcd(ll a, ll b) {
return b ? gcd(b, a % b) : a;
}
ll pow(ll a, ll b) {
ll ans = 1;
while (b) {
if (b & 1) ans *= a;
b >>= 1;
a *= a;
}
return ans;
}
ll pow(ll a, ll b, ll c) {
ll ans = 1;
while (b) {
if (b & 1) ans = (ans * a) % c;
b >>= 1;
a = (a * a) % c;
}
return ans;
}
void check(bool b) {
if (b)
cout << "Yes\n";
else
cout << "No\n";
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t = 1;
// cin >> t;
while (t--) {
ll n;
cin >> n;
string s;
cin >> s;
ll q;
cin >> q;
vector<array<array<ll, 3>, 2>> tree(4 * n);
auto merge = [&](const array<array<ll, 3>, 2> &left, const array<array<ll, 3>, 2> &right) {
ll x = min(left[0][1], right[0][0]);
ll x1 = min(left[1][1], right[1][0]);
array<array<ll, 3>, 2> res{};
res[0] = {left[0][0] + right[0][0] - x, left[0][1] + right[0][1] - x, left[0][2] + right[0][2] + x};
res[1] = {left[1][0] + right[1][0] - x1, left[1][1] + right[1][1] - x1, left[1][2] + right[1][2] + x1};
return res;
};
function<void(ll, ll, ll)> build = [&](ll v, ll l, ll r) {
if (l == r) {
tree[v][0] = {s[l] != 'C', s[l] == 'C', 0};
tree[v][1] = {s[l] == 'C', s[l] != 'C', 0};
return;
}
ll m = (l + r) / 2;
build(2 * v, l, m);
build(2 * v + 1, m + 1, r);
tree[v] = merge(tree[2 * v], tree[2 * v + 1]);
};
function<array<array<ll, 3>, 2>(ll, ll, ll, ll, ll)> query = [&](ll v, ll l, ll r, ll ql,
ll qr) -> array<array<ll, 3>, 2> {
if (ql > qr)return {0, 0};
if (ql == l && qr == r)return tree[v];
ll m = (l + r) / 2;
return merge(query(2 * v, l, m, ql, min(qr, m)), query(2 * v + 1, m + 1, r, max(ql, m + 1), qr));
};
build(1, 0, n - 1);
vector<ll> pre(n + 1);
set<ll> s1;
for (int i = 0; i < n; ++i) {
pre[i + 1] = pre[i] + (s[i] == 'C');
if (s[i] == 'C')s1.insert(i);
}
while (q--) {
ll l, r;
cin >> l >> r;
--l;
--r;
if (s1.upper_bound(r) == s1.begin())
cout << r - l + 1 << '\n';
else {
// cout << pre[r + 1] - pre[l]<<'\n';
cout << r - l + 1 - (pre[r + 1] - pre[l] + min(query(1, 0, n - 1, *s1.lower_bound(l) + 1, r)[1][2],
query(1, 0, n - 1, l, *--s1.upper_bound(r) - 1)[0][2]))
<< '\n';
}
}
}
return 0;
}
