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())
found = False

for a in range(1,x+1):
    for b in range(1,x+1):
        conds = [
            a%b == 0,
            a*b > x,
            a/b < x
        ]

        if False in conds:
            continue
        else:
            print(a,b)
            found = True
            break
    if found:
        break

if not found:
    print(-1)