/*
  Idea of homework: 
  Use colliding. 
  
  Example:
  Game have moving balls. 
  When two balls collide, then one of them will disappear (minimum)
  
  Ideas:
  When two balls collide, then bigger eats smaller and grows.
  New speed and direction depends on both colliding balls 
  
  Somewhere in center are point. If ball hits point, ball will be 
  change to two smaller balls (mass dividing randomly). 
  
*/