public class MainOutput{
    
    public static void main(String[] args) {
	
	String message1 = "Hello";
	String message2 = "Goodbye";
	System.out.println(message1 + " " + "John" + '!');
	System.out.println(message2);
	
	int a = 1;
	int b = 2;
	int c = 3;
	int d = 4;
	
	
	System.out.println(a + b + c + d);
	
	
	// The first multiplication at the left-side executes first. The result of the expression is a String("1,").
	// in result, the second multiplication shall have a String at the left-side and an int at the right-side. In result,
	// the type of the second expression becomes a String("1,2"). And this process continues...
	// The value of the third expression: "1,2,"
	// The value of the fourth expression: "1,2,3"
	// The value of the fifth expression: "1,2,3,"
	// The value of the sixth expression: "1,2,3,4"
	
	System.out.println(a + "," + b + "," + c + "," +  d); 
	
	
	
	
	
	
	
    }
    
    
}