#!/usr/bin/perl -w
use strict;

sub output {
    my( $nLow, $cBits )= @_;
    my $ipLow= join ".", unpack "C*", pack "N", $nLow;
    print "    $ipLow/$cBits\n";
}

while(  <DATA>  ) {
    my( $ipMin, $ipMax )= split " ", $_;
    print "$ipMin - $ipMax:\n";
    my $nMin= unpack "N", pack "C*", split /\./, $ipMin;
    my $nMax= unpack "N", pack "C*", split /\./, $ipMax;
    my $bitsMin= 1;
    my $maskMin= 1;
    my $bitsMax= 1;
    my $maskMax= 1;
    while( 1 ) {
        while(  0 == ( $nMin & $maskMin )  ) {
            ( $maskMin <<= 1 ) |= 1;
            $bitsMin++;
        }
        last   if  $nMax < ( $nMin | $maskMin );
        output( $nMin, $bitsMin-1 );
        ( $nMin |= $maskMin ) += 1;
    }
    while( 1 ) {
        while(  $maskMax == ( $nMax & $maskMax )  ) {
            ( $maskMax <<= 1 ) |= 1;
            $bitsMax++;
        }
        $nMax &= ~$maskMax;
        last   if  $nMax < $nMin;
        output( $nMax--, $bitsMax-1 );
    }
}
__END__
192.168.0.0 192.168.255.255
192.168.1.17 192.168.112.26