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())
c=0
for i in range(x+1):
    if i==0:
        continue
    for j in range(x+1):
        if j==0:
            continue
        if j%i==0:
            if j*i>x:
                if j/i<x:
                    print(j,i)
                    c+=1
                    break
    if c==1:
        break
if c==0:
    print(-1)