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 ask(int l,int r){
	putchar('?');
	for(int i=l;i<=r;++i)
		cout<<" "<<i;
	cout<<endl;
	fflush(stdout);
	string res;cin>>res;
	return res=="Red";
}
int ask(int l,int r,int x){
	putchar('?');
	if(l<=x && x<=r){
		for(int i=l;i<x;++i)
			cout<<" "<<i;
		for(int i=x+1;i<=r;++i)
			cout<<" "<<i;
	}
	else{
		for(int i=l+1;i<r;++i)
			cout<<" "<<i;
		cout<<" "<<x;
	}
	cout<<endl;
	fflush(stdout);
	string res;cin>>res;
	return (res=="Red")^(l<=x && x<=r);
}
int ans[2005];
int main(){
	int n;cin>>n;
	int res=ask(1,n),l=1,r=n,fin=1;
	while(l<=r){
		int mid=(l+r)>>1;
		if(ask(mid,mid+n-1)==res) fin=mid,l=mid+1;
		else r=mid-1;
	}
	ans[fin]=res; ans[fin+n]=res^1;
	for(int i=1;i<=n+n;++i)
		if(i!=fin && i!=fin+n) ans[i]=ask(fin,fin+n,i);
 	cout<<"! ";
	for(int i=1;i<=n+n;++i)
		cout<<(ans[i]?"R":"B");
	return 0;
	return 0;
}