my @a =();
my @b =();

while(<IN>){
  chomp;
  $cnt++;
  /\d+\t(\d+)/;
  if (@a<7){
    push(@a,$1);
  }
  push(@b,$1) if $1 > 3;
  if (@b>7){
    shift(@a);
    shift(@b);
  }
  print $a[0] - $b[-1] . "\n"
}