$ cat sd.pl
my $counter = -1;   # (so it's never zero until decrement does it)
while (<IN>) {
  if /SCHEDULE/ {   # (use right regex here)
     $counter = 2;
  }
  else if ($counter-- == 0) {
     // third line
  }
}
$ perl -cw sd.pl
syntax error at sd.pl line 3, near "if /SCHEDULE/"
syntax error at sd.pl line 6, near "else"
sd.pl had compilation errors.
$