z=3 atunci x+y=3, (x,y)={(0,3),(1,2),(2,1),(3,0)}
z=2 atunci x+y=13, (x,y)={(0,13),(1,12),(2,11),(3,10),(4,9),(5,8),(6,7),(7,6),(8,5),(9,4),(10,3),(11,2),(12,1),(13,0)}
z=1 atunci x+y=23, (x,y)={(0,23),(1,22),...,(21,2),(22,1),(23,0)}
z=0 atunci x+y=33, (x,y)={(0,33),(1,32),...,(31,2),(32,1),(33,0)}
