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
z=0
while(a<=x):
    b=1
    while(b<=x):
        if b%a==0:
            if b*a>x:
                if (a//b)<x:
                    z=1
                    print(b,a)
                    break
        b=b+1
    if z==1:
        break
    else:
        a=a+1
if z==0:
    print(-1)