#!/usr/bin/perl

$p = $ARGV[3];

open(F1, "$ARGV[0]");

while(<F1>){
    split;
    next if ($_[$p] eq "");
    push(@lag, $_[$p]);
    shift(@lag) if ($#lag > 2);
    print join(" ", @lag);
    print " red\n" if $#lag==2;
}

open(F2, "$ARGV[1]");

while(<F2>){
    split;
    next if ($_[$p] eq "");
    push(@lag, $_[$p]);
    shift(@lag) if ($#lag > 2);
    print join(" ", @lag);
    print " blue\n" if $#lag==2;
}

open(F3, "$ARGV[2]");

while(<F3>){
    split;
    next if ($_[$p] eq "");
    push(@lag, $_[$p]);
    shift(@lag) if ($#lag > 2);
    print join(" ", @lag);
    print " black\n" if $#lag==2;
}