#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T &x) {
  x = 0;
  bool f = 0;
  char c = getchar();
  for (; !isdigit(c); c = getchar())
    if (c == '-') f = 1;
  for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
  if (f) x = -x;
}
template <typename F>
inline void write(F x, char ed = '\n') {
  static short st[30];
  short tp = 0;
  if (x < 0) putchar('-'), x = -x;
  do st[++tp] = x % 10, x /= 10;
  while (x);
  while (tp) putchar('0' | st[tp--]);
  putchar(ed);
}
template <typename T>
inline void Mx(T &x, T y) {
  x < y && (x = y);
}
template <typename T>
inline void Mn(T &x, T y) {
  x > y && (x = y);
}
int n, m, d;
char s[] = {'R', 'Y', 'G', 'B'};
int main() {
  read(n), read(m), read(d);
  for (int i = 1; i <= n; i++, puts("")) {
    for (int j = 1; j <= m; j++) {
      int x = i + j + m, y = i + j + m;
      x = (x / d) & 1, y = (y / d) & 1;
      putchar(s[2 * x + y]);
    }
  }
  return 0;
}
