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:
n=int(input())
a=[]
b=[]
flag=0
for i in range(1,n+1):
    a.append(i)
    b.append(i)
#print (a)
#print(b)
for i in a:
    for j in b:
        if(i%j==0  and i*j>n and i//j <n):
            print (i,j)
            flag+=1
            break
    if(flag>0):
        break
if(flag==0):
    print("-1")