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())
v = None
b = 1
f = False
while b <= x:
    a = b
    f  = False
    while a <= x:
        if b%a == 0 and a*b > x and a//b < x:
            v = ()
            f = True
            break
        a+=1
    if f == True:
        break
    b+=1

if f == False:
    print(-1)
else:
    print(a,b)