#include <iostream>
#include <string.h>
#include <stdio.h>
#include <algorithm>
#include <math.h>

using namespace std;

int main()
{
    int T;
    char str[100],t[3]={'R','G','B'};
    long long n,m;
    cin>>T;
    while(T--){
        cin>>m>>n;
        int k = m-1;
        while(n&&(k+1)){
            int a = n%3;
            str[k--] = t[a];
            n /= 3;
        }
        for(int i = 0; i <= k; i++){
            str[i] = 'R';
        }
        str[m] = '\0';
        cout<<str<<endl;
    }
    return 0;
}