Addition and Subtraction BEDMAS

9+15-6+18-4+4+13-12
24-6+18-4+4+13-12
18-6+18-4+4+13-12
11+18-4+4+13-12
29+18-4+4+13-12
47-4+4+13-12
42+4+13-12
46+13-12
59-12
71