use strict ;
use warnings ;

my @arr = ( 3, 4, 71, 1, 1.5, -598, -100203, 0.5, -2, -1.5 );

my $result ;
while (my ($ix, $val) = each @arr) {
	next if ( $val < 0 || int $val != $val || ($result && $val > $result->[0]) ) ;
	$result = [ $val, $ix ] ;
}
if ( $result ) {
	print $result->[0] . " at " . $result->[1] . "\n" ;
}
__END__
1 at 3