#include<iostream>
#include<cstdio>

const char clr[5]="RYGB";

int main()
{
	int i,j;
	int H,W,d;
	scanf("%d%d%d",&H,&W,&d);
	for(i=0;i<H;i++)
	{
		for(j=0;j<W;j++)
		{
			int x = ((i + j) % (2 * d) + (2 * d)) % (2 * d) / d;
			int y = ((i - j) % (2 * d) + (2 * d)) % (2 * d) / d;
		    putchar(clr[2 * x + y]);
		}
		putchar('\n');
	}
	return 0;
}