350 = 2 * (5*5) * 7 420 = (2*2) * 3 * 5 * 7
HCK = (2*2) * 3 * (5*5) * 7 = 2100
16 = (2*2*2*2) 24 = (2*2*2) * 3
HCK = (2*2*2*2) * 3 = 48
48 = (2*2*2*2) * 3 72 = (2*2*2) * (3*3)
HCK = (2*2*2*2) * (3*3) = 144
15 = 3 * 5 18 = 2 * (3*3)
HCK = 2 * (3*3) * 5 = 90