// And you curse yourself for things you never done
#include<bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define sz(s) int((s).size())
#define bit(n,k) (((n)>>(k))&1)
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int maxn = 5e5 + 10, mod = 1e9 + 7, inf = 1e9 + 10;
vector<pii> qu[maxn];
int ans[maxn];
struct segment{
int mn[4 * maxn], lz[4 * maxn], sm[4 * maxn];
void shift(int l, int r, int id){
mn[id]+= lz[id];
sm[id]+= (r-l) * lz[id];
if(r-l > 1)
lz[2*id]+= lz[id], lz[2*id+1]+= lz[id];
lz[id] = 0;
}
void add(int f, int s, int x, int l = 0, int r = maxn, int id = 1){
if(f >= s || l >= r)
return;
shift(l, r, id);
if(s <= l || r <= f)
return;
if(f <= l && r <= s){
lz[id] = x;
shift(l, r, id);
return;
}
int mid = (l+r) >> 1;
add(f, s, x, l, mid, 2*id);
add(f, s, x, mid, r, 2*id+1);
mn[id] = min(mn[2 * id], mn[2 * id + 1]);
sm[id] = sm[2*id] + sm[2*id+1];
}
int askmn(int f, int s, int l = 0, int r = maxn, int id = 1){
if(f >= s || l >= r)
return inf;
shift(l, r, id);
if(s <= l || r <= f)
return inf;
if(f <= l && r <= s)
return mn[id];
int mid = (l+r) >> 1;
return min(askmn(f, s, l, mid, 2*id), askmn(f, s, mid, r, 2*id+1) );
}
int asksm(int f, int s, int l = 0, int r = maxn, int id = 1){
if(f >= s || l >= r)
return 0;
shift(l, r, id);
if(s <= l || r <= f)
return 0;
if(f <= l && r <= s)
return sm[id];
int mid = (l+r) >> 1;
return asksm(f, s, l, mid, 2*id) + asksm(f, s, mid, r, 2*id+1);
}
};segment seg1, seg2;
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie();
int n;
cin >> n;
string s;
cin >> s;
int q;
cin >> q;
for(int i = 0; i < q; i++){
int l, r;
cin >> l >> r;
--l;
qu[l].PB({r, i});
}
priority_queue<int, vector<int>, greater<int> > pq;
for(int i = n-1; i >= 0; i--){
if(s[i] == 'C'){
seg1.add(0, i + 1, 1);
if(!pq.empty()){
seg2.add(pq.top(), pq.top() + 1, -1);
seg1.add(0, pq.top() + 1, -1);
pq.pop();
}
}
else{
seg2.add(i, i+1, 1);
pq.push(i);
}
for(pii p : qu[i]){
ans[p.S] = seg2.asksm(i, p.F) - min(int(0), (seg1.askmn(i, p.F) - seg1.askmn(p.F, p.F + 1)));
}
}
for(int i = 0; i < q; i++){
cout << ans[i] << "\n";
}
return 0;
}
