public class Test public static void mainString! argsint a = 0whilea = 20switch acase 0case 1 a = a + 2case 2case 3 a = a + 3; breakdefault a = a + 5;Systemoutprinta= + a;

There are several syntax errors in your code. Here is the corrected version:

public class Test {
    public static void main(String[] args) {
        int a = 0;
        while(a <= 20) {
            switch (a) {
                case 0:
                case 1:
                    a = a + 2;
                    break;
                case 2:
                case 3:
                    a = a + 3;
                    break;
                default:
                    a = a + 5;
            }
            System.out.println("a=" + a);
        }
    }
}

Here are the changes I made:

• Added closing parentheses for the class declaration and the main method declaration.
• Replaced the exclamation mark (!) with an array brackets ([]) in the main method declaration.
• Added opening and closing curly braces ({}) for the while loop and the switch statement.
• Added break statements after each case in the switch statement.
• Replaced "System,out.print" with "System.out.println" to print the output on a new line