use strict;
use warnings;

my @array = <>;

my $N = shift @array;
chomp $N;

if ($N == scalar @array){
    my $sum = sum(@array);
    print $sum, "\n";

}else{
    die "somthing wrong"
}

sub sum {
    my @array = @_;
    my $sum = 0;
    for my $n (@array){
        chomp $n;
        $sum += $n;
    }
    return $sum;
}