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 constructive(x):
    a = x//2 + 1
    b = 2

    while a <= x:
        if a * b <= x or a % b != 0:
            a += 1
            continue
        return a, b
    return -1, 0


x = int(input())
a, b = constructive(x)
print(a, b) if b > 0 else print(a)