>type SSSufe.pl
use strict;
use warnings;
use List::Util qw(max);
use List::SomeUtils qw(nsort_by);

my @lines = <DATA>;
print ((nsort_by { biggest_on_line($_) } @lines)[-1]);


sub biggest_on_line {
    my $line = shift;
    my @nums = $line =~ /(\d+)/g;
    return max @nums;
}
__DATA__
Hello, i'm 18
1 this year is 2019 1
1 2 3 - 4

>perl SSSufe.pl
1 this year is 2019 1