use strict;
use warnings;

print &compatible ("_8__3__19", "48____7__"); #c 
print &compatible ("_8__3__19", "4_8___7__"); #i 
print &compatible ("_8__3__19", "48_____7_"); #i


sub compatible
{
	my @s=($_[0], $_[1]);

	my @d;

	for( 0,1 )
	{
	  for( $d[$_]=$s[$_] )
	  {
	    tr/0-9/\0/c;  #assuming the placeholder is not \0
	    tr/\0/\377/c;
	  }
	}
	
	my $m="$d[0]" & "$d[1]";
	
	for( 0,1 )
	{
	    $d[$_] = "$m" & "$s[$_]";
	}
	
	my $compatible;
	if( $compatible = $d[0] eq $d[1] )
	{
	    for( 0,1 )
	    {
		$d[$_] = {};
		${$d[$_]}{$1} .= "$-[0] " while $s[$_] =~ /(\d)/g;
	    }

	    $compatible &= !grep$d[1]->{$_} && $d[1]->{$_} ne $d[0]->{$_},keys %{$d[0]};
	}
	
	return $compatible ? 1 : 0;;
}