Bob loves foreign languages and wants to plan his course schedule for the following years. He is interested in the following nine language courses: LA15, LA16, LA22, LA31, LA32, LA126, LA127, LA141, and LA169. The course prerequisites are:
LA15: (none)
LA16: LA15
LA22: (none)
LA31: LA15
LA32: LA16, LA31
LA126: LA22, LA32
LA127: LA16
LA141: LA22, LA16
LA169: LA32
Find the sequence of courses that allows Bob to satisfy all the prerequisites