#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<ll,ll>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
const int nmax = 5e5 + 1;
struct node{
ll s, pref;
node(ll x) : s(x){
pref = max((ll)0, x);
}
node(){
s = pref = 0;
}
}t[4 * nmax];
node merg(node a, node b){
node c;
c.s = a.s + b.s;
c.pref = max(a.pref, a.s + b.pref);
return c;
}
void update(int v, int l, int r, int pos, int val){
if(l > pos || r < pos) return;
if(l == r){
t[v] = {val};
return;
}
int m = (l + r) / 2;
update(2 * v, l, m, pos, val);
update(2 * v + 1, m + 1, r, pos, val);
t[v] = merg(t[2 * v], t[2 * v + 1]);
}
node get(int v, int l, int r, int st, int fin){
if(l > fin || r < st) return {0};
if(l >= st && r <= fin)
return t[v];
int m= (l + r) / 2;
node x = get(2 * v, l, m, st, fin);
node y = get(2 * v + 1, m + 1, r, st, fin);
return merg(x, y);
}
int main(){
int n; cin >> n;
char c[n + 1];
for(int i = 1; i <= n; i++)
cin >> c[i];
for(int i = 1; i <= n; i++){
if(c[i] == 'C') update(1, 1, n, i, -1);
else
update(1, 1, n, i, 1);
}
int q; cin >> q;
vector <int> ans(q);
vector <pii> qv[n + 1];
for(int i = 0; i <q; i++){
int l, r; cin >> l >> r;
qv[r].pb({l, i});
}
vector <int> cur;
for(int i = 1; i <= n; i++){
if(c[i] == 'C'){
if(!cur.empty()){
int pos = cur.back();
update(1, 1, n, pos, 1);
cur.pop_back();
}
}
else{
cur.pb(i), update(1, 1, n, i, 0);
}
for(auto to : qv[i]){
int l = to.f;
int x = cur.end() - lower_bound(cur.begin(), cur.end(), l);
x += get(1, 1, n, l, i).pref;
ans[to.s] = x;
}
}
for(int i = 0; i < q; i++)
cout << ans[i] << "\n";
return 0;
}
