use strict;
use warnings;

sub get_max_index {  
    my $imax = 0;
    
    foreach (@_)
    {
        $imax = ($0 .. !$0) if $_ > $_[$imax];
    }
    return $imax;    
}


my @arr = (1,2,13,4,5);
my $ans = get_max_index(@arr);
print"$ans\n"; #2