#!/usr/bin/perl
use warnings;
use strict;

my $min = 0xFFFF_FFFF;
my $max = 0x0000_0000;

for (@ARGV) {
    if (/(\d+)\.(\d+)\.(\d+)\.(\d+)/) {
	my $adr = $1 * 0x100_0000 + $2 * 0x1_0000 + $3 * 0x100 + $4;
	$max = $adr if ($adr > $max);
	$min = $adr if ($adr < $min);
    }
}

my $diff = $min ^ $max;

# printf "min = %08x max = %08x diff = %08x\n", $min, $max, $diff;

my $netmaskbits = 32;
my $netmask = 0xFFFF_FFFF;

while ($diff > 0) {
    $netmaskbits--;
    $diff >>= 1;
    $netmask <<= 1;
}

my $net = $min & $netmask;
my $bcast = $min | ~$netmask;

printf "net = %s/%d (%s/%s) bcast = %s\n",
       dottedquad($net),
       $netmaskbits,
       dottedquad($net),
       dottedquad($netmask),
       dottedquad($bcast);

sub dottedquad {
    my ($adr) = @_;
    return sprintf "%d.%d.%d.%d",
		   ($adr >> 24) & 0xFF,
		   ($adr >> 16) & 0xFF,
		   ($adr >>  8) & 0xFF,
		   ($adr >>  0) & 0xFF;
}

exit(0);