What is the mistake here

Question

public class Program
{
public static void main(String[] args) {
int a=12;
b=a++*5--a;
System.out.println(b);
}
}
What is the mistake here

Answer 1

Your fixed code :
https://code.sololearn.com/cPi0ne27ENFh/?ref=app

Answer 2

Emma please can you say me the working of this program