#include <cstdio>
#include <cstdlib>
#include <climits>
using namespace std;

const static int COLOR_NAME_LENGTH = 7;
const static int BASE_COLOR_NUM = 8;
const static int MASK = 0x0000ff;

const int base_colors[ BASE_COLOR_NUM ] = {
  0x000000,
  0x0000ff,
  0x00ff00,
  0x00ffff,
  0xff0000,
  0xff00ff,
  0xffff00,
  0xffffff
};

const char *base_color_names[ BASE_COLOR_NUM ] = {
  "black",
  "blue",
  "lime",
  "aqua",
  "red",
  "fuchsia",
  "yellow",
  "white"
};

int diffsq( const int color1, const int color2 ) {
  int c1 = color1;
  int c2 = color2;
  int rdiff = ( ( c1 >> 16 ) & MASK ) - ( ( c2 >> 16 ) & MASK );
  int gdiff = ( ( c1 >>  8 ) & MASK ) - ( ( c2 >>  8 ) & MASK );
  int bdiff = ( ( c1       ) & MASK ) - ( ( c2       ) & MASK );

  return rdiff * rdiff + gdiff * gdiff + bdiff * bdiff;
}

int main() {

  while( 1 ) {
    char color_name[ COLOR_NAME_LENGTH + 1 ];
    scanf( "%s", color_name );
    if( color_name[ 0 ] == '0' ) {
      return EXIT_SUCCESS;
    }
    for( int i = 1; i < COLOR_NAME_LENGTH + 1; i++ )  {
      color_name[ i - 1 ] = color_name[ i ];
    }
    int color;
    int minidx = 0;
    int mindiff = INT_MAX;
    sscanf( color_name, "%x", &color );
    for( int i = 0; i < BASE_COLOR_NUM; i++ ) {
      int diff = diffsq( color, base_colors[ i ] );
      if( diff < mindiff ) {
        minidx = i;
        mindiff =  diff;
      }
    }
    printf( "%s\n", base_color_names[ minidx ] );
  }
}