import std.stdio, std.string, std.array, std.conv, std.algorithm, std.typecons, std.range;

void main(){
    auto hwd=readln.split.map!(to!int).array;
    auto H=hwd[0],W=hwd[1],d=hwd[2];

    foreach(w;0..H){
        foreach(h;0..W){
            auto k=w+h;
            auto j=w-h;
            auto x=k.div(d);
            auto y=j.div(d);
            draw(x.mod(2)+2*y.mod(2));
        }
        writeln();
    }
}

int mod(int a,int d){
    if(a>=0)return a%d;
    return (a%d+d)%d;
}

int div(int a,int d){
    return (a-a.mod(d))/d;
}

void draw(int i){
    "RYGB"[i].write;
}
