#!/usr/bin/perl -w
use strict;

my %hash;
while( <> ) {
    chomp $_;
    my @trib= grep { "" ne $_ } split /(...)/, $_;
    my $ref= \\%hash;
    while(  @trib  ) {
        $ref= \$$ref->{shift @trib};
    }
    $$ref++;
}