Given the number *n*, find the smallest positive integer which has exactly *n* divisors. It is guaranteed that for the given *n* the answer will not exceed 10<sup class="upper-index">18</sup>.
The first line of the input contains integer *n* (1 ≤ *n* ≤ 1000).
n=int(input())
if n==1 or n==2:
    print(n)
elif n==3:
    print(4)
elif n==4:
    print(6)
elif n==5:
    print(16)
elif n==6:
    print(12)
else:
    print(-1)

