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:
a=1
b=1
x=int(input())
c=0
while (a<=x):
    for b in range(1,x+1):
        if (a%b==0 and a//b<x and a*b>x):
            c+=1
            print(a,b)
            break
    if c>0:
        break
    a+=1
if not c:
    print(-1)