def interval_scheduling(jobs):
    """
    Jobs is an array of start and end times.
    E.g. jobs = [(s1, f1), ..., (sn, fn)]
    """

    jobs.sort(key=lambda x: x[1])

    possible_jobs = set()
    prev_finish_time = 0
    for i in range(len(jobs)):
        print(possible_jobs)
        s = jobs[i][0]
        e = jobs[i][1]

        if s >= prev_finish_time:
            possible_jobs.add(jobs[i])
            prev_finish_time = e

    return len(possible_jobs)


jobs = [(2, 5), (1, 3), (4, 8), (1, 6), (5, 8)]
print(interval_scheduling(jobs))