def count_longest_run(lst):
    """
    Return longest run in given experiment outcomes list
    """
    Y_longest_run = count = 0
    current = lst[0]
    for outcome in lst:
        if outcome == current:
            count += 1
        else:
            count = 1
            current = outcome
        Y_longest_run = max(count, Y_longest_run)
    return Y_longest_run