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:
a=int(input())
r=1
t=0
while r<=a:
    s=1
    while s<=a:
        if  r>=1 and r<=a and s>=1 and s<=a and r%s==0 and r*s>a and r/s<a:
            print(r,s)
            t=t+1
            break
        s=s+1
    if t>0:
        break
    r=r+1
if t==0:
    print(-1)