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:
def out(x):
    if x == 1:
        return -1
    for b in range(1, x+1):
        for a in range(x//b+1, b*x+1):
            if a%b==0:
               return  a, b
    return -1


if __name__ == '__main__':
    x = input()
    out = out(int(x))
    if type(out)==tuple:
        print(out[0], out[1])
    else:
        print(out)