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=x
b=a
a1=1
b1=1
c=0
while a>=1:
  while b>=1:
    #print('a=', a, 'b=', b, 'a % b==0', a % b==0, 'a*b>x', a*b>x, 'a/b<x', a/b<x)

    if (a % b == 0 and a*b>x and a/b<x):
        a1=a
        b1=b
        c=1
        break
    b=b-11
  if (c==1):
    break
  b=a
  a=a-1


if (a1==1 and b==1 ):
  print(-1)
else:
 print(a1, b1)