How many pens does it take to write one exam

Today I brought three pens with me to my exam and all of them ran out of ink while I was writing.

The important question is, how many pens should I bring to be safe but without looking as though I care about school? Karl Lagerfeld once said that you should make your hard work seem effortless. Even though everything he says is ridiculous, he does have a point here. After all, the purpose of life is to make everyone jealous that you're such an amazing person.