multiply matrix or add

import java.util.Scanner;

public class multiadd {
    public static void main(String[] args) {
        int r;
        Scanner sc = new Scanner(System.in);
        System.out.println("enter row:");
        r = sc.nextInt();
        int[][] a = new int[r][r];
        int[][] a1 = new int[r][r];
        System.out.println("enter values for matrix1:");
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < r; j++) {
                a[i][j] = sc.nextInt();
            }
        }
        System.out.println("enter values for matrix2:");
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < r; j++) {
                a1[i][j] = sc.nextInt();
            }
        }
        System.out.println("enter 1 for multiply \n 2 for add");
        int choice = sc.nextInt();
        int[][] m = new int[r][r];
        switch (choice) {
            case 1:
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < r; j++) {
                        m[i][j] = 0;
                        for (int k = 0; k < r; k++) {
                            m[i][j] += (a[i][k] * a1[k][j]);
                        }
                    }
                }
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < r; j++) {
                        System.out.print(m[i][j] + " ");
                    }
                    System.out.println("");
                }
                System.out.println("transpose of multuiplied matrix:");
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < r; j++) {
                        System.out.print(m[j][i] + " ");
                    }
                    System.out.println("");
                }
                break;
            case 2:
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < r; j++) {
                        m[i][j] = a[i][j] + a1[i][j];

                    }
                }
                for (int i = 0; i < r; i++) {
                    for (int j = 0; j < r; j++) {
                        System.out.print(m[i][j] + " ");
                    }
                    System.out.println("");
                }
            default:
                break;
        }
        sc.close();

    }
}