Exception thrown in finally and catch block

have question on exception thrown in catch and finally block:

class MyExc1 extends Exception {}
class MyExc2 extends Exception {}
class MyExc3 extends MyExc2 {}

public class C1 {
    public static void main(String[] args) throws Exception {
        try {
            System.out.print(1);
            q();
        }
        catch (Exception i) {
            throw new MyExc2();
        }
        finally {
            System.out.print(2);
            throw new MyExc1();
        }
    }
    static void q() throws Exception {
        try {
            throw new MyExc1();
        }
        catch (Exception y) {
            System.out.print(3);
        }
        finally {
            System.out.print(4);
            throw new Exception();
        }
    }

}

I have tried to execute above code more than one time. It gives me different outputs each time.

output 1: 1Exception in thread "main" 342test.MyExc1
at test.C1.main(C1.java:18)
output 2: 1342Exception in thread "main" test.MyExc1
at test.C1.main(C1.java:18)
output 3: 1Exception in thread "main" test.MyExc1
342 at test.C1.main(C1.java:18)
output4:  1Exception in thread "main" 34test.MyExc1
2 at test.C1.main(C1.java:18)

Please explain.