#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double
const int MAXN = 5e5;
const ll INF = 4e18;
const int MOD = 1e9 + 7;
ll ps[MAXN + 5], pos[MAXN + 5];
ll cnt[MAXN + 5];
struct ST{
ll N;
vector<ll> sg;
ST(ll _n){
N = _n;
sg.resize(4 * N + 5, INF);
}
void upd(ll l, ll r, ll cur, ll idx, ll val){
if(l == r) sg[cur] = val;
else{
ll mid = (l + r) / 2;
if(idx <= mid) upd(l, mid, cur * 2, idx, val);
else upd(mid + 1, r, cur * 2 + 1, idx, val);
sg[cur] = min(sg[cur * 2], sg[cur * 2 + 1]);
}
}
ll query(ll l, ll r, ll cur, ll x, ll y){
if(l > y || r < x) return INF;
if(l >= x && r <= y) return sg[cur];
ll mid = (l + r) / 2;
return min(query(l, mid, cur * 2, x, y), query(mid + 1, r, cur * 2 + 1, x, y));
}
};
struct BIT{
ll N;
vector<ll> bit;
BIT(ll _n){
N = _n;
bit.resize(N + 5);
}
void upd(ll idx, ll val){
for(; idx <= N; idx += idx & -idx) bit[idx] += val;
}
ll get(ll idx){
ll ans = 0;
for(; idx >= 1; idx -= idx & -idx) ans += bit[idx];
return ans;
}
ll query(ll l, ll r){
return get(r) - get(l - 1);
}
};
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll N; cin >> N;
string S; cin >> S;
S = '%' + S;
for(int i = 1; i <= N; i++){
ps[i] = ps[i - 1] + (S[i] == 'C' ? 1 : -1);
cnt[i] = cnt[i - 1] + (S[i] == 'C');
}
stack<ll> stk;
for(int i = N; i >= 0; --i){
while(!stk.empty() && ps[stk.top()] >= ps[i]) stk.pop();
if(!stk.empty()){
pos[i] = stk.top();
}
stk.push(i);
}
BIT bit(N);
ST sg(N);
for(int i = 1; i <= N; i++){
if(S[i] == 'C' && pos[i]){
bit.upd(pos[i], 1);
sg.upd(1, N, 1, i, -ps[pos[i] - 1]);
}
}
ll Q; cin >> Q;
vector<pii> queries[N + 5];
vector<ll> ans(Q + 5);
for(int i = 1; i <= Q; i++){
ll l, r; cin >> l >> r;
queries[l].push_back({r, i});
}
for(int i = 1; i <= N; i++){
// for(int j = 1; j <= N; j++) cout << bit.query(j, j) << " ";
// cout << "\n";
for(auto [j, idx] : queries[i]){
ll lf = i, rg = j, pt = i - 1;
for(;lf <= rg;){
ll mid = (lf + rg) / 2;
if(ps[j] + sg.query(1, N, 1, i, mid) + j - i + 1 - cnt[j] + cnt[i - 1] - bit.query(i, mid) >= 0){
pt = mid;
lf = mid + 1;
}
else rg = mid - 1;
}
ans[idx] = j - i + 1 - (cnt[j] - cnt[i - 1] + bit.query(i, pt));
}
if(S[i] == 'C' && pos[i]){
bit.upd(pos[i], -1);
sg.upd(1, N, 1, i, INF);
}
}
for(int i = 1; i <= Q; i++) cout << ans[i] << "\n";
}
}
/*
*/
