This is how you skip lines without affecting the rest of the outer while loop.

while(<DATA>){
   if (/2/){
      my $skip=2;
      print "skipping $skip lines\n";
      <DATA> while $skip-- >0 and not eof DATA;
      next;
   }
   if (/5/){
      print "high five\n"; next;
   }
   if (/3/){
      print "I am not here\n"; next;
   }
   print;
}

__DATA__
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