use strict;
use warnings;

my $iter = 3;

&foo( $iter );

sub foo {
    my ( $iter, @val ) = @_;
    return unless $iter;
    $iter--;
    for my $i ( 1 .. 10 ) {
        print join("+", @val, $i), "\n" if scalar @_ > 1;
        &foo( $iter, @val, $i );
    }
}