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:
n = int(input()) + 1
b = 0
for i in range(1, n):
    if b :
        break
    for j in range(i, n):
        if j % i == 0 and j * i > n - 1 and j / i < n - 1 :
            print (j, i)
            b = 1
            break
if not b :
    print(-1)