#!/usr/bin/perl -w
use strict;
my %kids=map { split } <DATA>;
print "Father of $_ is $kids{$_}\n" for @ARGV;

__DATA__
1045316394 1045316144
1045316407 1045316394
1045316419 1045316407
1045316438 1045316419
1045316469 1045316394
1045316492 1045316407
1045316505 1045316492


##</code><code>##

$ perl fatherson.pl 1045316419 1045316492
Father of 1045316419 is 1045316407
Father of 1045316492 is 1045316407


##</code><code>##

sub print_lineage {
    my ($x) = @_;
    my @p;
    while (exists $kids{$x}) {
	$x = $kids{$x};
	push @p,$x;
    }
    if (@p) {
	local ($") = ", ";
	print "Lineage of $_[0] is @p\n";
    } else {
	print "Lineage of $_[0] is unknown\n";
    }
}
print_lineage $_ for @ARGV;


##</code><code>##

$ perl fatherson.pl 1045316419 1045316469
Lineage of 1045316419 is 1045316407, 1045316394, 1045316144
Lineage of 1045316469 is 1045316394, 1045316144


##</code><code>##

---
print map { my ($m)=1<<hex($_)&11?' ':'';
$m.=substr('AHJPacehklnorstu',hex($_),1) }
split //,'2fde0abe76c36c914586c';