Explicație pas cu pas:
(20 si 3): 19, 18, 17, 16, 15, 14, 13, 12, 11, 10 , 9 , 8, 7 , 6, 5 , 4.
(20 si 8): 19, 18, 17, 16 , 15, 14 , 13, 12, 11, 10 , 9
(30 si -7): 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6
(30 si 4): 29, 28 ,27, 26 ,25 ,24 ,23 ,22 ,21 ,20 ,19 18 ,17 ,16 1,5 ,14 ,13 ,12 ,11 ,10 ,9 ,8 7 6 5.
