Can execute the java program without main method

We can execute a Java program without main() method by using the static block ...
ex.

   Class S
       {
         static int x,y,z;
        static
             {
        x=10;          y=20;
         z=x+y;
        System.out.print(z);
        System.exit(0);
               }
       }

Output:
     30

For Further Reading,