Problem: Given an integer x, find 2 integers a and b such that: 

  * 1 ≤ a,b ≤ x 
  * b divides a (a is divisible by b). 
  * a ⋅ b>x. 
  * a/b<x. 

Input

The only line contains the integer x (1 ≤ x ≤ 100).

Output

You should output two integers a and b, satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).

Examples

Input

10


Output

6 3

Input

1


Output

-1

Solution (in PYTHON3):

Solution:
def myfunc(a, b):
    while a <= n:
        b = int(1)
        while b <= n:
            if (a % b == 0) and (a * b > n) and (a / b < n):
                print(str(a) + " " + str(b))
                return
            b += 1

        a += 1


n = int(input())

if n != 1:
    a = int(1)
    b = int(1)
    myfunc(a, b)


else:
    print(-1)