Sorry my answer was not very clear. Yes, the 2-punch solution is not possible given you you can't delete lines. However, the last line of the 5-punch solution looks exactly like the 2-punch solution (if it were possible). It relies on the same trick you use to solve level 3. Start with 0.If you would like to spoil it. Copy the below text and use the paste button in the game to paste it:(turns out browser pasting is disabled for security, here is a picture instead https://imgur.com/UOuRpG3)
r,r,r,fk;