#!/usr/bin/perl

open (NOTEN, "noten.txt") or die "Kann Notendatei nicht öffnen: $!\n";

while ($line = ) {
	($student, $grade) = split (" ", $line);
	$grades {$student} .= $grade . " ";
}

foreach $student (sort keys %grades) 
{
	$scores = 0;
	$total = 0;
	@grades = split (" ", $grades {$student});
	foreach $grade (@grades) {
		$total += $grade;
		$scores ++;
	}
	if ($scores) {$average = $total / $scores;}
	print "$student: $grades{$student}\tDurchschnitt:$average\n";
}