lost my pencil eraser

i got one of those pencils with the big erasers and it came with a container with 15 leads and 4 erasers +3 erasers cause 3 pencils. i lost one of the erasers on the container and now the balance is off. i constantly put the erasers in my mouth but now the weight of the erasers will be off and ill constantly be in misery until i die. even if i buy a new container i still have to live with the fact that the one eraser i lost is out there somewhere and that container will forever be unbalanced