How to calculate, Please help

Question

int a, b;
a = 0;
b = 0;
b++;
++b;
b++;
++b;
++a;
cout<<++a+(++a*b++)*(++a*b++)<<++b;

Answer 1

manually, result is 2427 but using playground, result is 3647

Answer 2

What is hard-run result

Answer 3

2427 is the final result.