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:
input_num=input('')
input_num=int(input_num)
mid_num=int(input_num/2)
first_num=0
last_num=0
if input_num>100 or input_num<1:
    print(-1)
else:
    
    for num in range(input_num,mid_num,-1):
        
        if num%2==0:
            first_num=num
            last_num=2
            if first_num*last_num >input_num and first_num/last_num <input_num:
                break
            else:
                first_num=0
                last_num=0
    if first_num==0:
            print(-1)
    else:
        print(first_num),print(last_num)