Input numbers in 2d array and find sum of all numbers in Java

import java.util.Scanner;

public class Q1
{
    public static void main(String args[])
    {
        int a[][]=new int[3][3], r,c,s=0;
        Scanner sc=new Scanner(System.in);

        System.out.println("Enter 9 numbers");
        for(r=0; r<3; r++)
        {
            for(c=0; c<3; c++)
            {
                a[r][c]=sc.nextInt();
                s=s+a[r][c];
            }
        }
        System.out.println("Sum of all the numbers = "+s);
    }
}