my %count;
while (my $line = <DATA>) {
	chomp $line;
	my @cols = split("\t",$line);
	$count{$_} += $cols[$_] for 0 .. $#cols;
}
for my $col_num (sort { $a <=> $b } keys %count) {
	print "Total for column $col_num: $count{$col_num}\n";
}

__DATA__
1	2	3	4
3	4	5	6
6	7	8	9

##</code><code>##

Total for column 0: 10
Total for column 1: 13
Total for column 2: 16
Total for column 3: 19