#!/usr/bin/perl
use strict;    
use warnings;  
               
my %h = (      
    a=>{ a=>1, b=>2, c=>3, d=>4 }, 
    b=>{ h=>5, i=>6, j=>5 },  
    c=>{ r=>5, s=>5, t=>5 },  
    e=>{ r=>5, s=>5, t=>4 },                                                                                          
);   
               
for my $k (sort keys %h) {
    my @t = kv_for_largest_v($h{$k});
    print "Key $k: $t[0], $t[1]\n";
}    
               
sub kv_for_largest_v {
    my $hr = shift;
    return undef unless keys %$hr;
    my ($k,$v) = each %$hr;
    while (my ($k2,$v2) = each %$hr) {
        ($k,$v) = ($k2,$v2) if $v2>$v;
    }   
    return $k,$v;
}