use v5.14;

sub total {
    my $sum = 0;
    foreach (@_) {
        $sum += $_;
    }

    say "list @_\nsum is $sum";
    $sum;
}
say "Enter a list of number to calculate sum :";

my @numList = split /[,\s]+/, <STDIN>;
chomp @numList;
@numList = grep length, @numList;
my $total = total(@numList);
say "Total : $total";

__END__
Enter a list of number to calculate sum :
10 12 20
list 10 12 20
sum is 42
Total : 42