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 n;
string interact(vector<int>a)
{
	cout<<"? ";
	for(int i=0;i<a.size();i++)
		cout<<a[i]<<" ";
	cout<<endl;
	string res;
	cin>>res;
	return res;
}
string ask(int l,int r)
{
	vector<int>a;
	for(int i=l;i<=r;i++)
		a.push_back(i);
	return interact(a);
}
string solve(int n)
{
	string a1=ask(1,n);
	int at=0;
	for(int i=7;i>=0;i--)
	{
		int to=min(n+1,at+(1<<i));
		string a2=ask(to,to+n-1);
		if(a1==a2) at+=(1<<i);
	}
	
	vector<int>tmp1,tmp2;
	for(int i=at+1;i<=at+n-1;i++)
		tmp1.push_back(i);
	for(int i=1;i<at;i++)
		tmp2.push_back(i);
	for(int i=at+n+1;i<=2*n;i++)
		tmp2.push_back(i);
	
	string ans="";
	for (int i=1;i<=2*n;i++) 
	{
		if(at+1<=i&&i<=at+n-1) 
		{
			vector<int>cur=tmp2;
			cur.push_back(i);
			string res=interact(cur);
			if(res=="Blue") ans+="B";
			else ans+="R";
		}
		else 
		{
			vector<int>cur=tmp1;
			cur.push_back(i);
			string res=interact(cur);
			if(res=="Blue") ans+="B";
			else ans+="R";
		}
	}
	return ans;
}
signed main()
{
	scanf("%d",&n);
	string ans=solve(n);
	cout<<"! "<<ans;
	return 0;
}