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 solve(x):
    for a in range(1, x+1):
        for b in range(1, x+1):
            if b%a == 0 and a%b == 0 and a*b > x and a / b < x:
                return (a, b)
    return None

if __name__ == '__main__':
     x = int(input())
     r = solve(x)
     if r is not None:
        print(r[0], r[1])
     else:
        print(-1)