The final solution

I was driving my grandchildren near a cemetery.

- Grandpa, they hide dead people in boxes and put them here - said Felix (6 years old).

- Yes, you are right.

- You are old grandpa, you will die soon.

- Yes, thanks for reminding me, I will book a place here tomorrow.

- But grandma is older than you.

- No, she is much younger than me.

- She is very, very, very old - confirmed Matilda (4 years old).

- She will die before you grandpa - announced Felix.

- You are wrong - I interrupt - I will die earlier.

- No grandpa, she will die earlier, but you will not marry anybody else! - stated Felix.

- Felix - she cannot die before me - who will cook us the soup? - I used the strongest argument.

- Yes Felix - Matilda was seriously alarmed - who will cook the soup?

- Grandpa, you will buy yourself baby food! - declared Felix triumphantly.