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 PYTHON):

Solution:
def check(x):
    flag=0
    for i in range(1,x+1):
        b=i
        for j in range(1,x+1):
            if j%b==0 and b*j>x and j/b<x:
                flag=1
                a=j
                break
            else:
                continue
        if flag==1:
            break
    if flag==0:
        print(-1)
    else:
        x=str(a)+" "+str(b)
        print(x)
def main():
    x=int(input())
    check(x)
    
if __name__=='__main__':
    main()