#include<stdio.h>
#include<math.h>
int main()
{
    int t, m;
    long long n;
    scanf("%d", &t);
    while (t--)
    {
        scanf("%d%I64d", &m, &n);
        int a[3] = {'R', 'G', 'B'};
        char ans[31];
        
        for (int i = 0; i < m; i++)
        {
            ans[i] = a[n%3];
            n /= 3;
        }
        for (int j = m-1; j >= 0; j--)
        {
            printf("%c", ans[j]);
        }
        printf("\n");
    }
    
}