#include<bits/stdc++.h>
using namespace std;
vector<int> haha(500001);
vector<int> brl(2000001);
vector<int> brr(2000001);
vector<int> wow(2000001);
vector<int> sb(2000001);
pair<pair<int,int>,pair<int,int>> merge(pair<pair<int,int>,pair<int,int>> a, pair<pair<int,int>,pair<int,int>> b) {
pair<int,int> c = a.first,d = a.second,e = b.first,f = b.second;
int sb = c.second+e.second;
int br1 = d.first+max(0,f.first-(c.second+d.first));
int br2 = f.second+max(0,d.second-(e.second+f.second));
int x = max(0,e.first-f.second-(c.second+d.first));
int y = max(0,c.first-d.first-(e.second+f.second+x));
return {{d.first+f.second+x+y,sb},{br1,br2}};
}
void build(int l, int r, int x) {
if(l == r) {
sb[x] = haha[l];
if(haha[l] == -1) {
brl[x] = 1;
brr[x] = 1;
wow[x] = 1;
}
return;
}
int mid = (l+r)/2;
build(l,mid,x*2);
build(mid+1,r,x*2+1);
pair<pair<int,int>,pair<int,int>> c = merge({{wow[x*2],sb[x*2]},{brl[x*2],brr[x*2]}},{{wow[x*2+1],sb[x*2+1]},{brl[x*2+1],brr[x*2+1]}});
sb[x] = c.first.second;
brl[x] = c.second.first;
brr[x] = c.second.second;
wow[x] = c.first.first;
}
pair<pair<int,int>,pair<int,int>> calc(int l, int r, int ql, int qr, int x) {
if(l == ql && r == qr) {
return {{wow[x],sb[x]},{brl[x],brr[x]}};
}
int mid = (l+r)/2;
if(qr <= mid) {
return calc(l,mid,ql,qr,x*2);
}
else if(ql > mid) {
return calc(mid+1,r,ql,qr,x*2+1);
}
else {
return merge(calc(l,mid,ql,mid,x*2),calc(mid+1,r,mid+1,qr,x*2+1));
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n,q,l,r;
cin >> n;
for(int i = 1; i <= n; i++) {
char a;
cin >> a;
if(a == 'C') {
haha[i] = 1;
}
else {
haha[i] = -1;
}
}
build(1,n,1);
cin >> q;
for(int i = 0; i < q; i++) {
cin >> l >> r;
cout << calc(1,n,l,r,1).first.first << "\n";
}
return 0;
}
