class MealyStateMachine:
    def __init__(self):
        self.state = 'A'

    def march(self):
        if self.state == 'A':
            self.state = 'B'
            return 0
        elif self.state == 'B':
            self.state = 'C'
            return 1
        elif self.state == 'C':
            self.state = 'E'
            return 3
        elif self.state == 'D':
            self.state = 'E'
            return 5
        else:
            return MealyError('march')

    def merge(self):
        if self.state == 'C':
            return 4
        elif self.state == 'E':
            self.state = 'F'
            return 6
        else:
            return MealyError('merge')

    def jump(self):
        if self.state == 'C':
            self.state = 'D'
            return 2
        elif self.state == 'E':
            return 7
        elif self.state == 'F':
            self.state = 'A'
            return 8
        else:
            return MealyError('jump')


class MealyError(Exception):
    def __init__(self, method_name):
        self.method_name = method_name

    def __str__(self):
        return self.method_name


def main():
    return MealyStateMachine()


def test():
    m = main()  # A
    try:
        m.merge()
    except MealyError:
        pass
    try:
        m.jump()
    except MealyError:
        pass
    m.march()  # B
    try:
        m.merge()
    except MealyError:
        pass
    try:
        m.jump()
    except MealyError:
        pass
    m.march()  # E
    try:
        m.march()
    except MealyError:
        pass
    m.merge()  # F
    try:
        m.merge()
    except MealyError:
        pass
    try:
        m.march()
    except MealyError:
        pass
    m = main()
    m.march()
    m.march()
    m.jump()
    try:
        m.merge()
    except MealyError:
        pass
    try:
        m.jump()
    except MealyError:
        pass
    m = main()
    assert m.march() == 0
    assert m.march() == 1
    assert m.merge() == 4
    assert m.jump() == 2
    assert m.march() == 5
    assert m.jump() == 7
    assert m.merge() == 6
    assert m.jump() == 8
    m = MealyStateMachine()
    assert m.march() == 0
    assert m.march() == 1
    assert m.merge() == 4
    assert m.march() == 3
    assert m.jump() == 7
    assert m.merge() == 6
    assert m.jump() == 8