A. Ehab and another construction problem

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Given an integer xx, find 2 integers aa and bb 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 xx (1≤x≤100)(1≤x≤100).

Output

You should output two integers aa and bb, satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).

Examples

input

Copy

10

output

Copy

6 3

input

Copy

1

output

Copy

-1

題意：給了一個數想x,找出兩個數a,b滿足一下條件：

• 1≤a,b≤x
• b能夠除a
• a⋅b>x
• a/b<x

輸出找找到的兩個數，沒有就輸出-1.

題解：發現除1以外的數都有兩個數滿足條件，而且x只要大於1，a,b最簡單的就是x。

c++：

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int x;
    cin>>x;
    if(x==1) puts("-1");
    else cout<<x<<" "<<x<<endl;
    return 0;
}
 

python：

x=input()
print(-1 if x=="1" else x+" "+x)