What's a polite way of saying no to someone who asks for a pencil or someother type of writing utencil during class?

i’ve noticed alot of ppl dont have their pencils or pens with them. and i keep lying and telling them that I dont have any to share and I feel bad. If i give one they lose it and ask again. I can’t afford to buy pencils for all my friends or pppl who keep losing the ones I give to them