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())
a = 1
b = 1
condition = False

def verify(a,b):
    if b % a == 0:
        if a * b > x:
            if a/b < x:
                return True
    return False

while b <= x and condition == False:
    condition = verify(a,b)
    if condition == False:
        if a < x:
            a += 1
        else:
            a = 1
            b += 1
if condition == True:
    print("%d %d" % (a,b))
else:
    print("-1")