#! /usr/bin/perl

my %X;

for (<>) {
    my ($i,$k,$n) = split(" ",$_,3);
    $X{$k.$n}{$k.$i} = $_;
}

for (sort {$a->[0] cmp $b->[0]} map [%$_], values %X) {
    print $_->[1] if @$_ == 2;
}