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:
# cf 1088 A 800
# a divisible by b
# a * b > x
# a / b < x
def f(x):
    for a in range(1, x + 1):
        for b in range(1, a + 1):
            if a % b == 0 and a * b > x and a // b < x:
                return (a, b)
    return None

x = int(input())
ans = f(x)
if ans is None:
    print(-1)
else:
    print(ans[0], ans[1])