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:
if __name__ == '__main__':
    x = input()
    x = int(x)

    for b in range(1, 101):

        mul = 1
        while b * mul <= 100:
            if b * mul * b > x and mul < x:
                print("%d %d" % (b * mul, b))
                exit()
            else:
                mul += 1

    print(-1)