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:
import math
n=int(input())
if(n//2==0):
    print("-1")
    
elif(((n//2)*(n//2))<=n):
    if(n//2==1):
        print(n,n)
    else:
        print(n//2 *2,n//2)
else:
    print(n//2,n//2)