#include<iostream>
#include<cmath>
using namespace std;

#define loop(i,a,b) for(int i = a ; i < b ; i ++)
#define rep(i,a) loop(i,0,a)
int stoi(char c){
  if('0' <= c && c <= '9')
    return c - '0';
  return c - 'a' + 10;
}

int pow(int n){
  return n * n;
}

int main(void){
  string s;
  string ans[8] = {
    "black",//	00	00	00
    "blue",//	00	00	ff
    "lime",//	00	ff	00
    "aqua",//	00	ff	ff
    "red",//	ff	00	00
    "fuchsia",//	ff	00	ff
    "yellow",//	ff	ff	00
    "white"//	ff	ff	ff
  };
  int num[8];
  int cnt = 0;
  rep(i,8)num[i] = i * 255;     
  while(cin>>s){
    if(s == "0")break;
    int in[3];
    in[0] = stoi(s[1]) * 16 + stoi(s[2]);
    in[1] = stoi(s[3]) * 16 + stoi(s[4]);
    in[2] = stoi(s[5]) * 16 + stoi(s[6]);
    //rep(i,3)cout<<in[i]<<endl;
    int index = 0;
    unsigned long long diff = 100000000;
    rep(i,8){

      int box[3];
      rep(j,3){
	box[j] = (i>>(2-j))%2*255;
      }
      
     
      unsigned long long int calc = 0;
      rep(j,3)calc += pow(in[j] - box[j]);
     	
      if(calc < diff){
	diff = calc;
	index = i;
      }
    }
    cout<<ans[index]<<endl;
  }
}