/**
 *    author:  tourist
 *    created: 23.09.2017 15:13:56       
**/
#include <bits/stdc++.h>

using namespace std;

string let = "RYGB";

int main() {
  int h, w, d;
  cin >> h >> w >> d;
  for (int i = 0; i < h; i++) {
    for (int 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(let[2 * x + y]);
    }
    putchar('\n');
  }
  return 0;
}
