#include<bits/stdc++.h>
using namespace std;
struct Q
{
int l,r,id;
};
struct node
{
int sum;
int suf;
node(){}
node(int a,int b){sum=a,suf=b;}
};
node Merge(node a,node b)
{
if (a.sum==1000000)return b;
if (b.sum==1000000)return a;
node ret;
ret.sum=a.sum+b.sum;
ret.suf = min(b.suf,b.sum+a.suf);
return ret;
}
node tree[4000000];
int a[1000000];
#define mid (l+r)/2
#define L x*2
#define R x*2+1
void build(int x,int l,int r)
{
if (l==r)
tree[x]=node(a[l],min(a[l],0));
else
{
build(L,l,mid);
build(R,mid+1,r);
tree[x]=Merge(tree[L],tree[R]);
}
}
void upd(int x,int l,int r,int v,int val)
{
if (v>r || v<l)return;
if (l==r)
tree[x]=node(val,min(val,0));
else
{
upd(L,l,mid,v,val);
upd(R,mid+1,r,v,val);
tree[x]=Merge(tree[L],tree[R]);
}
}
node query(int x,int l,int r,int s,int e)
{
if (s>r || e<l)
return node(1000000,0);
if (l>=s && r<=e)
return tree[x];
return Merge(query(L,l,mid,s,e),query(R,mid+1,r,s,e));
}
bool operator<(Q a,Q b)
{
return a.l>b.l;
}
Q q[1000000];
int ret[1000000];
int stk[1000000];
int sz=0;
int getLessThan(int v)
{
int ret=sz;
int l = 0, r=sz-1;
while(l<=r)
{
if (stk[mid]<=v)
ret=mid,r=mid-1;
else
l=mid+1;
}
return sz-ret;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int n;
cin>>n;
string s;
cin>>s;
for (int i=1;i<=n;i++)
{
if (s[i-1]=='C')a[i]=1;
else a[i]=-1;
}
int m;
cin>>m;
for (int i=0;i<m;i++)
{
cin>>q[i].l>>q[i].r;
q[i].id=i;
}
build(1,1,n);
sort(q,q+m);
int l=n+1;
for (int i=0;i<m;i++)
{
while(l>q[i].l)
{
l--;
if (a[l]==-1)
{
stk[sz++] = l;
upd(1,1,n,l,0);
}
else if (sz>0)
{
upd(1,1,n,stk[--sz],-1);
}
}
ret[q[i].id] = getLessThan(q[i].r) - query(1,1,n,q[i].l,q[i].r).suf;
}
for (int i=0;i<m;i++)
cout<<ret[i]<<endl;
}
