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())
missing = True
for a in range (1, 100):
    if missing:
        for b in range (1, 100):
            if missing:
                if a % b == 0:
                    if a*b > x:
                        if a / b < x:
                            print(a, b)
                            missing = False

if missing:
    print(-1)