#include <iostream>
#include <cmath>

using namespace std;

string str;
const string color[8] = {"black","blue","lime","aqua","red","fuchsia",
			 "yellow","white"};
const string strong[8] = {"#000000","#0000ff","#00ff00","#00ffff","#ff0000",
			  "#ff00ff","#ffff00","#ffffff"};

int change(char ch){
  if('0' <= ch && ch <= '9'){
    return ch - '0';
  }
  return 10 + (ch - 'a');
}

int d(string str1,string str2){
  int R1 = change(str1[1])*16 + change(str1[2]);
  int G1 = change(str1[3])*16 + change(str1[4]);
  int B1 = change(str1[5])*16 + change(str1[6]);

  int R2 = change(str2[1])*16 + change(str2[2]);
  int G2 = change(str2[3])*16 + change(str2[4]);
  int B2 = change(str2[5])*16 + change(str2[6]);

  int res = pow(R1-R2,2.0) + pow(G1-G2,2.0) + pow(B1-B2,2.0);

  return res;
}

#define INF (1<<29)

int main(){
  while(cin >> str , str != "0"){
    int min_ = INF,ans;
    for(int i = 0 ; i < 8 ; i++){
      int dist = d(str,strong[i]);
      if(dist < min_){
	min_ = dist;
	ans = i;
      }
    }
    cout << color[ans] << endl;
  }

  return 0;
}