#include<iostream>
using namespace std;
string str;
string ta[8] = {"black","blue","lime","aqua",
		"red","fuchsia","yellow","white"};

string tb[8] = {"#000000","#0000ff","#00ff00","#00ffff",
                "#ff0000","#ff00ff","#ffff00","#ffffff"};
int tab[8];
int mini,miniNo;

/*
string d(int in){
  if(in==0)return "0";  if(in==8)return "8";
  if(in==1)return "1";  if(in==9)return "9";
  if(in==2)return "2";  if(in==15)return "f";
  if(in==3)return "3";  if(in==14)return "e";
  if(in==4)return "4";  if(in==13)return "d";
  if(in==5)return "5";  if(in==12)return "c";
  if(in==6)return "6";  if(in==11)return "b";
  if(in==7)return "7";  if(in==1.)return "a";
}
*/
int c(char ch){
  if('a'<=ch&&ch<='f')return 10+(ch-'a');
  return ch-'0';
}

int b(string x,string y){
  int X = c(x[0])*16 + c(x[1]);
  int Y = c(y[0])*16 + c(y[1]);
  int Z = X - Y;
  //string z= d(Z/16)+d(Z%16);
  return Z*Z;
}
string compute(){
  
}
int main(){
  while(1){
    mini=99999;
    cin>>str;
    if(str=="0")break;
    for(int i=0;i<8;i++){
      tab[i] =b( tb[i].substr(1,2) , str.substr(1,2) );
      tab[i]+=b( tb[i].substr(3,2) , str.substr(3,2) );
      tab[i]+=b( tb[i].substr(5,2) , str.substr(5,2) );
      if(mini>tab[i]){
	mini=tab[i];
	miniNo=i;
      }
    }
    cout<<ta[miniNo]<<endl;
  }
}