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())
def ret(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 -1
z=ret(x)
if(z==-1):
       print(z)
else:
       print(z[0],z[1])