#!/usr/bin/perl
use strict;
use warnings;

my %hash = ();

while (my $line = <DATA>){
  chomp $line;
  my ($k, $v) = split / /, $line;
  # geänderte zeile
  $hash{$k} = $v if(!exists($hash{$k}) or $hash{$k} < $v);
}

my @keys_sorted = sort{ $hash{$b} <=> $hash{$a} }keys %hash;

for my $key ( @keys_sorted ){
  print "$key -> $hash{$key}\n";
}

__DATA__
woche 4
woche 3
week 2
semana 1
woche 7
week 4
semana 9
vecka 3