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:
n = int(input())

flag = False
for i in range(1,1001):
    for j in range(1,1001):
        if j%i == 0:
            if j*i > n and j//i < n:
                print(j,i)
                flag = True
                break

    if flag:
        break

if flag == False:
    print(-1)