#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;
}
