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())
for i in range(2,math.ceil(math.sqrt(n)+1)):
    for j in range(int(n/i)+1,n+1):
        if(j%i==0 and j/i<n):
            print(str(j) + " " +str(i))
            exit()
print(-1)