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())
check=0
for i in range(1,x+1):
    b=i
    for j in range(i,x+1):
        a=j
        if(a%b==0 and a*b>x and a/b<x):
            print(a,b)
            check=1
            break
            
            
    if(check==1):
        break
    
if(check==0):
    print(-1)