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

my @merk;

while (<>) {
     if (/^t+$/) {
         <>; <>; <>; <>; <>;
         @merk = ();
     }
     else {
          push @merk, $_;
     }
     print shift @merk if $#merk >=3;
}

print for @merk;