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 PYTHON):

Solution:
def find_a_b(x):

    for a in range(1, x + 1):
        lower = max(x / a - 1, 1)
        for b in range(lower, x + 1):
            if a % b == 0 and float(a) / float(b) < x and a * b > x:
                return str(a) + ' ' + str(b)
    return str(-1)


x = int(raw_input())
print(find_a_b(x))