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())

if x > 100:
    print("Error")
    exit()

a = 1
b = x

# a: 1 ... x
# b: 1 ... x

for i in range(1,x+1):
    while a <= x and b >= 1:
        if (a%b == 0) and ((a*b) > x) and ((a/b) < x):
            print (a,b)
            exit()
        b = b-1
    
    b = x
    a = a+1

print(-1)