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 JAVA):

Solution:
import java.io.IOException;
import java.io.InputStream;

public class Main
{
    public static void main(String args[]) throws IOException
    {
        FastIO fio = new FastIO(System.in);
        StringBuilder output = new StringBuilder();

        int n = fio.readInt();

        if(n == 1)
            System.out.println("-1");
        else
            System.out.println(""+n+" "+n);
    }
}

class FastIO
{
    private InputStream stream;
    private byte[] buf = new byte[1024];

    private int curChar;

    private int numChars;

    public FastIO(InputStream stream)
    {
        this.stream = stream;
    }

    public int read()
    {
        if (numChars == -1)
            throw new RuntimeException();
        if (curChar >= numChars)
        {
            curChar = 0;
            try
            {
                numChars = stream.read(buf);
            } catch (IOException e)
            {
                throw new RuntimeException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public String readString()
    {
        final StringBuilder stringBuilder = new StringBuilder();
        int c = read();
        while (isSpaceChar(c))
            c = read();
        do
        {
            stringBuilder.append(c);
            c = read();
        } while (!isSpaceChar(c));
        return stringBuilder.toString();
    }

    public int readInt()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do
        {
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public long readLong()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do
        {
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public boolean isSpaceChar(int c)
    {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
}