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
import sys
import collections


# imgur.com/Pkt7iIf.png

def ii(): return int(input())
def mi(): return map(int, input().split())
def li(): return list(map(int, input().split()))

n = ii()
print(-1) if n == 1 else print(n - n%2, 2)