#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iterator>
#include <bitset>
#include <unordered_set>
#include <unordered_map>
#include <fstream>
#include <iomanip>
#include <cassert>
//#include <utility>
//#include <memory>
//#include <functional>
//#include <deque>
//#include <cctype>
//#include <ctime>
//#include <numeric>
//#include <list>
//#include <iomanip>

//#if __cplusplus >= 201103L
//#include <array>
//#include <tuple>
//#include <initializer_list>
//#include <forward_list>
//
//#define cauto const auto&
//#else

//#endif

using namespace std;


typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vint;
typedef vector<vector<int> > vvint;
typedef vector<long long> vll, vLL;
typedef vector<vector<long long> > vvll, vvLL;

#define VV(T) vector<vector< T > >

template <class T>
void initvv(vector<vector<T> > &v, int a, int b, const T &t = T()){
    v.assign(a, vector<T>(b, t));
}

template <class F, class T>
void convert(const F &f, T &t){
    stringstream ss;
    ss << f;
    ss >> t;
}

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define reep(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) reep((i),0,(n))
#define ALL(v) (v).begin(),(v).end()
#define PB push_back
#define F first
#define S second
#define mkp make_pair
#define RALL(v) (v).rbegin(),(v).rend()
#define DEBUG
#ifdef DEBUG
#define dump(x)  cout << #x << " = " << (x) << endl;
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#else
#define dump(x) 
#define debug(x) 
#endif
#define LDcout(x,n) fixed<<setprecision(n)<<x

#define MOD 1000000007LL
#define EPS 1e-8
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
#define maxs(x,y) x=max(x,y)
#define mins(x,y) x=min(x,y)

int foo(int a,int b,int c){
    int t=a*a+b*b+c*c;
    return t;
}
void mainmain(){
    vector<string> v;
    v.PB("black");
    v.PB("blue");
    v.PB("lime");
    v.PB("aqua");
    v.PB("red");
    v.PB("fuchsia");
    v.PB("yellow");
    v.PB("white");
    string s;
    while(cin>>s){
        if(s.size()==1) return;
        vint w(3,0);
        rep(i,3){
            string tmp=s.substr(1+i*2,2);
            if(isdigit(tmp[0])) w[i]=16*(tmp[0]-'0');
            else{
                w[i]=16*(tmp[0]-'a'+10);
            }
            if(isdigit(tmp[1])) w[i]+=(tmp[1]-'0');
            else{
                w[i]+=(tmp[1]-'a'+10);
            }
        }
        // cout<<w[0]<<" "<<w[1]<<" "<<w[2]<<endl;
        vector<pii> vv(8);
        rep(i,8){
            vint tmp(3);
            rep(j,3){
                if((1<<j)&i) tmp[j]=255;
                else tmp[j]=0;
            }
            vv[i].S=i;
            vv[i].F=foo(w[0]-tmp[0],w[1]-tmp[1],w[2]-tmp[2]);
        }
        sort(ALL(vv));
        cout<<v[vv[0].S]<<endl;
    }
}


signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
      cout<<fixed<<setprecision(20);
    mainmain();
}