#include <iostream>
using namespace std;
const int MAXN=5e5+10;
struct Node {
int sum;
int minpr;
int minsuf;
int x;
};
int arr[MAXN];
Node tree[4*MAXN];
Node combine (Node a, Node b) {
Node ans;
ans.sum=a.sum+b.sum;
ans.minpr=min(a.minpr,a.sum+b.minpr);
ans.minsuf=min(b.minsuf,b.sum+a.minsuf);
ans.x=min(a.minpr+b.minsuf,min(a.x+b.sum,b.x+a.sum));
ans.x=min(0,ans.x);
return ans;
}
void build_tree(int node, int l, int r) {
if (l==r) {
tree[node]={arr[l],min(0,arr[l]),min(0,arr[l]),min(0,arr[l])};
return;
}
int mid=(l+r)/2;
build_tree(node*2,l,mid);
build_tree(node*2+1,mid+1,r);
tree[node]=combine(tree[node*2],tree[node*2+1]);
}
Node query(int node, int l, int r, int ql, int qr) {
if (ql>r || qr<l) return {0,0,0,0};
if (l>=ql && r<=qr) return tree[node];
int mid=(l+r)/2;
return combine(query(node*2,l,mid,ql,qr),query(node*2+1,mid+1,r,ql,qr));
}
int main () {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n;
cin >> n;
char ch;
for (int i=1;i<=n;i++) {
cin >> ch;
if (ch=='C') arr[i]=1;
else arr[i]=-1;
}
build_tree(1,1,n);
int q, l, r;
cin >> q;
for (int i=0;i<q;i++) {
cin >> l >> r;
Node ans=query(1,1,n,l,r);
cout << -ans.x << endl;
}
}
