#!/usr/bin/perl

use v5.12;
use strict;
use warnings;

my @max     = qw/0 0/;
my %results = {
    1 => 0,
    2 => 1,
};

sub chainLength {

    my $arg   = shift;
    my $num   = $arg;
    my $count = 0;

    while ( $num > 2 ) {
        if ( exists $results{$num} ) {
            return ( $results{$arg} = $count + int( $results{$num} ) );
        }

        ( ( $num % 2 ) == 0 ) ? ( $num /= 2 ) : ( $num = 3 * $num + 1 );
        $count++;
    }
    return ( $results{$arg} = $count );
}

for my $i ( 2 .. 1000000 ) {
    my $res = chainLength($i);
    if ( $res > $max[1] ) {

        $max[0] = $i;
        $max[1] = $res;
    }

}
print "@max";