i just want to see if u can get this.. i have tryed it with my Друзья they cant so i just want to see :)

Alex is always getting himself into trouble. one week his teacher gives him detention every день after school. as his punshment he is asked to carry 100 heavy sandbags to the long jump pit. after struggling with the first ten bags. Alex has a idear he realizes that if he puts something into each sandbag it will be ligter to carry... what is it?....