/**
* code generated by JHelper
* More info: https://github.com/AlexeyDmitriev/JHelper
* @author win11905
*/
#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define vi vector<int>
#define iii tuple<int, int, int>
#define long long long
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const long MOD = 1e9+7, LINF = 1e18 + 1e16;
const int INF = 1e9+1;
const double EPS = 1e-10;
const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
const int N = 1<<19;
class election {
private:
int n, m;
int ans[N];
char arr[N];
vector<pii> que[N];
int t[N<<1], lz[N<<1];
void push(int p) {
if(!lz[p]) return;
t[p] += lz[p];
if(p < N) lz[p<<1] += lz[p], lz[p<<1|1] += lz[p];
lz[p] = 0;
}
template<typename T>
void travel(int x, int y, const T &f, int p = 1, int l = 0, int r = N-1) {
push(p);
if(x > r || l > y || x > y) return;
if(x <= l && r <= y) return f(p);
int m = l + r >> 1;
travel(x, y, f, p<<1, l, m), travel(x, y, f, p<<1|1, m+1, r);
t[p] = min(t[p<<1], t[p<<1|1]);
}
public:
void solve(istream& cin, ostream& cout) {
cin >> n;
cin >> arr+1;
cin >> m;
for(int i = 0, l, r; i < m; ++i) {
cin >> l >> r;
que[r].emplace_back(l, i);
}
vector<int> stk;
auto query = [&](int l, int r) {
int mn = 1e9;
travel(l, r, [&](int p) { mn = min(mn, t[p]); });
return mn;
};
for(int i = 1; i <= n; ++i) {
if(arr[i] == 'C') {
if(!stk.empty()) {
travel(stk.back(), n, [&](int p) { lz[p]--, push(p); });
stk.pop_back();
}
travel(i, n, [&](int p) { lz[p]++, push(p); });
} else stk.emplace_back(i);
for(auto x : que[i]) {
int z = query(x.x, i) - query(x.x-1, x.x-1);
int pre = lower_bound(all(stk), x.x) - stk.begin();
ans[x.y] = ((int)stk.size() - pre) - min(0, z);
}
}
for(int i = 0; i < m; ++i) cout << ans[i] << endl;
}
};
class Solver {
public:
void solve(std::istream& in, std::ostream& out) {
election *obj = new election();
obj->solve(in, out);
}
};
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(0);
Solver solver;
std::istream& in(std::cin);
std::ostream& out(std::cout);
solver.solve(in, out);
return 0;
}
