// #includes {{{
#include <bits/stdc++.h>
using namespace std;

#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define RREP(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define FOR(i,c) for(__typeof((c).begin()) i=(c).begin();i!=(c).end();++i)
#define LET(x,a) __typeof(a) x(a)
//#define IFOR(i,it,c) for(__typeof((c).begin())it=(c).begin();it!=(c).end();++it,++i)
#define ALL(c) (c).begin(), (c).end()
#define MP make_pair

#define EXIST(e,s) ((s).find(e)!=(s).end())

#define RESET(a) memset((a),0,sizeof(a))
#define SET(a) memset((a),-1,sizeof(a))
#define PB push_back
#define DEC(it,command) __typeof(command) it=command

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define debug2(x) cerr << #x << " = [";REP(__ind,(x).size()){cerr << (x)[__ind] << ", ";}cerr << "] (L" << __LINE__ << ")" << endl;

const int INF=0x3f3f3f3f;

typedef long long Int;
typedef unsigned long long uInt;
typedef long double rn;

typedef pair<int,int> pii;

/*
#ifdef MYDEBUG
#include"debug.h"
#include"print.h"
#endif
*/
// }}}

//{{{ io
FILE *file_in=stdin,*file_out=stdout;
#define fin normal_in
#define fout normal_out
//const char fname[]="";
//FILE *fin=fopen(fname,"r"),*fout=fopen(fname,"w");
#ifdef __MINGW32__
#define LLD "%I64d"
#define LLU "%I64u"
#else
#define LLD "%lld"
#define LLU "%llu"
#endif
struct NORMAL_IN{
	bool cnt;
	NORMAL_IN():cnt(true){}
	operator int() const {return cnt;}
#define endl "\n"
	NORMAL_IN& operator>>(int &n){cnt=fscanf(file_in,"%d",&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(unsigned int &n){cnt=fscanf(file_in,"%u",&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(long long &n){cnt=fscanf(file_in,LLD,&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(unsigned long long &n){cnt=fscanf(file_in,LLU,&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(double &n){cnt=fscanf(file_in,"%lf",&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(long double &n){cnt=fscanf(file_in,"%Lf",&n)!=EOF;return *this;}
	NORMAL_IN& operator>>(char *c){cnt=fscanf(file_in,"%s",c)!=EOF;return *this;}
	NORMAL_IN& operator>>(string &s){
		s.clear();
		for(bool r=false;;){
			const char c=getchar();
			if(c==EOF){ cnt=false; break;}
			const int t=isspace(c);
			if(!r and !t)r=true;
			if(r){
				if(!t)s.push_back(c);
				else break;
			}
		}
		return *this;
	}
	template<class T>
		NORMAL_IN& operator>>(vector<T> &v){
			int n;fscanf(file_in,"%d",&n);
			REP(i,n){
				T t;*this>>t;
				v.push_back(t);
			}
			return *this;
		}
} normal_in;

struct NORMAL_OUT{
	NORMAL_OUT& operator<<(const int &n){fprintf(file_out,"%d",n);return *this;}
	NORMAL_OUT& operator<<(const unsigned int &n){fprintf(file_out,"%u",n);return *this;}
	NORMAL_OUT& operator<<(const long long &n){fprintf(file_out,LLD,n);return *this;}
	NORMAL_OUT& operator<<(const unsigned long long &n){fprintf(file_out,LLU,n);return *this;}
	NORMAL_OUT& operator<<(const double &n){fprintf(file_out,"%lf",n);return *this;}
	NORMAL_OUT& operator<<(const long double &n){fprintf(file_out,"%Lf",n);return *this;}
	NORMAL_OUT& operator<<(const char c[]){fprintf(file_out,"%s",c);return *this;}
	NORMAL_OUT& operator<<(const string &s){fprintf(file_out,"%s",s.c_str());return *this;}
} normal_out;
//}}}

template<class T>
T rem(const T &a, const T &b){
	return (a%b+b)%b;
}

template<class T>
T floor_div(const T &a,const T &b){
	assert(b>0);
	T ret = (a-rem(a,b))/b;
	if(not (ret*b<=a and a<(ret+1)*b)){
		cout<<a<<" "<<b<<endl;
		assert(false);
	}
	return ret;
}

template<class T>
T ceil_div(const T &a,const T &b){
	return (a+b-T(1))/b;
}

void solve(long long H, long long W, long long d){
	REP(i,H){
		REP(j,W){
			int k = d;
			int i0 = floor_div(i-j,k), j0 = floor_div(i+j,k);
			if(i0%2==0){
				if(j0%2==0){
					fout<<"R";
				}else{
					fout<<"Y";
				}
			}else{
				if(j0%2==0){
					fout<<"G";
				}else{
					fout<<"B";
				}

			}
		}
		fout<<endl;
	}
}

int main(){	
	long long H;
	long long W;
	long long d;
	fin >> H;
	fin >> W;
	fin >> d;
	solve(H, W, d);
	return 0;
}


Measured memory_bytes: 512