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=int(input())
i=a/2
i=int(i)
x=-1
y=-1
if a==2:
    print("2 2")
elif a==3:
    print("2 2")
else :    
    for p in range(i+1,a+1):
        for q in range(i,1,-1):
            if p%q==0:
                x=p
                y=q
                break
        if x!=-1:
            break        
    if x==-1:
        print("-1")
    else:
        print(x,end=" ")
        print(y)