Problem: This is an interactive task.

We have 2N balls arranged in a row, numbered 1, 2, 3, ..., 2N from left to right, where N is an odd number. Among them, there are N red balls and N blue balls.

While blindfolded, you are challenged to guess the color of every ball correctly, by asking at most 210 questions of the following form:

* You choose any N of the 2N balls and ask whether there are more red balls than blue balls or not among those N balls.



Now, let us begin.

Constraints

* 1 \leq N \leq 99
* N is an odd number.



* * *



Example

Input




Output

Solution (in CPP):

Solution:
#include<bits/stdc++.h>
using namespace std;
int Flag0,n;
inline int query(vector<int> V)
{
	cout<<"? ";
	for(int i=0;i<(int)V.size();i++) cout<<V[i]<<' ';
	cout<<endl;fflush(stdout);
	string ans;cin>>ans;return ans=="Red";
}
inline vector<int> getvector(int l,int r)
{
	vector<int> ans;
	for(int i=l;i<=r;i++) ans.push_back(i);
	return ans;
}
inline vector<int> merge(vector<int> a,vector<int> b)
{
	for(int i=0;i<(int)b.size();i++) a.push_back(b[i]);
	return a;
}
string ans;
int main()
{
	scanf("%d",&n);
	Flag0=query(getvector(1,n));
	int L=1,R=n,Pos=0;
	while(L<R)
	{
		int mid=(L+R+1)>>1,flagmid=query(getvector(mid,mid+n-1));
		if(flagmid==Flag0) L=mid;else R=mid-1;
	}
	vector<int> t=getvector(L+1,L+n-1),tt=merge(getvector(1,L-1),getvector(L+n+1,n+n));
	for(int i=1;i<=n+n;i++)
	{
		vector<int> v=t;
		v.push_back(i);
		if(i>=L&&i<=L+n) v=tt,v.push_back(i);
		if(query(v)) ans+="R";else ans+="B";
	}
	cout<<"! "<<ans<<endl;
	fflush(stdout);
}