What is the output of the program ?

1. class SampleExec1 {
2. void run() {
3. System.out.println("SampleExec1 run");
4. }
5. }
6. 
   
7. class SampleExec2 extends SampleExec1 {
8. void run() {
9. System.out.println("SampleExec2 run");
10. }
11. }
12. 
    
13. public class SampleExecution {
14. public static void main(String[] args) {
15. SampleExec2 ex = new SampleExec1();
16. ex.run();
17. }
18. }

Output: compile time error at line 15. Type mismatch: cannot convert from SampleExec1 to SampleExec2