a = 6 => b = 18 - 3 = 15
a < b(6 < 15) - да
b < 2 - нет, b = 15 - 2 = 13
b < 2 - нет, b = 13 - 2 = 11
b < 2 - нет, b = 11 - 2 = 9
b < 2 - net, b = 9 - 2 = 7
b < 2 - net, b = 7 - 2 = 5
b < 2 - net, b = 5 - 2 = 3
b < 2 - net, b = 3 - 2 = 1
b < 2 - da, Вывод: b(1)
Ответ: 2