#!/usr/bin/perl

open($f, "progression.in");
open($g, ">progression.out");

@eilutes=<$f>;
$eilute=join('',@eilutes);

 print($g "$eilute\n");

$eilute=~s/(-?\d+)/$1\n$1/gm;
$eilute=~s/\d+//m;
$eilute=reverse $eilute;
$eilute=~s/-?\d+//;
$eilute=reverse $eilute;
$eilute=~s/(-?\d+)\n(-?\d+)/$dif=$1-$2;$dif/gem;

 print($g "$eilute\n");

$max=0;
$eilute=~s/(-?\d+)/$1\n$1/gm;
$eilute=~s/-?\d+//m;
$eilute=reverse $eilute;
$eilute=~s/-?\d+//;
$eilute=reverse $eilute;
$eilute=~s/(-?\d+)\n(-?\d+)/$1==$2 ? $max++ : {$max=0} ;$max/gem;

 print($g "$eilute");

$max=0;
$eilute=~s/(\d+)/ $max=$1 if ($max<$1) ;$1/gem;

 print($g "$eilute");

print($g $max+2);