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:
x = int(input())
i = x

def findDivisor(a):
    b = a
    while b>0 and a % b != 0:
        b -= 1
    return b

while i >= 1:
    div = findDivisor(i)
    if div * i > x and i / div < x:
        print(i, div)
        break
    i -= 1

if i == 0:
    print(-1)