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

my($current_net, $q, $start_net);
my $last_net="";
my $w=0;


$|=1;
if(0) {
    _fiddle(0x1c, 0x7b, 0, 8);
    #_fiddle(2, 7, 0, 4);
    #_fiddle(0, 7, 0, 4);
    #_fiddle(0, 15, 0, 4);
    die;
}
while(<>) {
    s/:/ /; 
    $current_net=(split " ", $_)[1]; 
#    print $current_net;
    $current_net=~s/\.1$/.0/g;
    $q=(split "\\.", $current_net)[2]; 
    if($q != $w+1) {
        
        fiddle($start_net, $last_net) if $start_net;
        $start_net=$current_net;
    }
    $w=$q;
    $last_net=$current_net; 
}

fiddle($start_net, $last_net) if $start_net;


sub fiddle
{
    my($start, $end)=@_;
    warn "$start -> $end\n";
    my @q=split /\./, $start;
    $start=($q[0]<<24) + ($q[1]<<16) + ($q[2]<<8) + $q[3];
    @q=split /\./, $end;
    $end=($q[0]<<24) + ($q[1]<<16) + ($q[2]<<8) + $q[3];
    
    _fiddle($start, $end, 0, 32);
#    die;
}

sub _fiddle
{
    my($start, $end, $q, $size)=@_;
#    warn sprintf "_fiddle(start=%08x end=%08x q=%i size=$size)\n", $start,  $end, $q if $q==0;
    if($start==$end) {
        $size=8  if $size==32 and 0==($end & 0xffffff);
        $size=16 if $size==32 and 0==($end & 0xffff);
        $size=24 if $size==32 and 0==($end & 0xff);
        print_cidr($start, $size);
        return;
    }
    my $span=$end-$start+1;
    my $p2=log($span)/log(2);
    if($p2==int $p2) {
#        warn sprintf "class start=%08x end=%08x q=$q p2=$p2\n", $start,  $end;
        print_cidr($start, $size-$p2);
        return;
    }

    my($mask, $c, $n);
    $c=0;
    my $max=$size-$q;
    foreach $n ($q..($size-1)) {
        $mask=(1<<(($size-1)-$n));
        if(($start&$mask) == ($end&$mask)) {
#            warn sprintf "same  start=%08x end=%08x mask=%08x n=$n q=$q c=$c common=%i\n", $start,  $end, $mask, $c+$q;
            $c++;
        } else {
#            warn sprintf "recur start=%08x end=%08x mask=%08x n=$n q=$q c=$c common=%i\n", $start,  $end, $mask, $c+$q;
            $mask--;
            my $e=($start|$mask);
#            warn sprintf ">_fiddle(start=%08x end=%08x q=%i)\n", $start,  $e, $n;
#            warn sprintf ">_fiddle(start=%08x end=%08x q=%i)\n", $e+1,  $end, $n;
            _fiddle($start, $e, $n, $size) unless $e < $start;
            $e++;
            _fiddle($e, $end, $n, $size) unless $e > $end;
            last;
        }
    }
}

sub print_cidr
{
    my($ip, $size)=@_;

#    printf "%08x/$size\n", $ip, $size;
    printf "%i.%i.%i.%i/$size\n", ($ip>>24)&0xff, ($ip>>16)&0xff, ($ip>>8)&0xff, $ip&0xff;
}