#include<iostream>
#include<string>
#include<vector>
using namespace std;
int Overten(char a){
  if(a-'0'<10)return a-'0';
  if(a=='A')return 10;
  if(a=='B')return 11;
  if(a=='C')return 12;
  if(a=='D')return 13;
  if(a=='E')return 14;
  if(a=='F')return 15;
}
int changeDtoI(char a,char b){
  return Overten(a)*16+Overten(b);
}
int main(void){
  string color;
  while(cin>>color,color.size()>3){
    int R = changeDtoI(color[1],color[2])<128?0:1;
    int G = changeDtoI(color[3],color[4])<128?0:1;
    int B = changeDtoI(color[4],color[5])<128?0:1;
    //cout<<R << " " << G << " " << B <<endl;
    if(R * G * B)cout<<"white"<<endl;
    else if(R * G)cout<<"yellow"<<endl;
    else if(R * B)cout<<"fuchsia"<<endl;
    else if(G * B)cout<<"aqua"<<endl;
    else if(R)cout<<"red"<<endl;
    else if(G)cout<<"green"<<endl;
    else if(B)cout<<"blue"<<endl;
    else cout<<"black"<<endl;
  }
}