def zero(f=None):
    return f(0) if f else 0


def one(f=None):
    return f(1) if f else 1


def two(f=None):
    return f(2) if f else 2


def three(f=None):
    return f(3) if f else 3


def four(f=None):
    return f(4) if f else 4


def five(f=None):
    return f(5) if f else 5


def six(f=None):
    return f(6) if f else 6


def seven(f=None):
    return f(7) if f else 7


def eight(f=None):
    return f(8) if f else 8


def nine(f=None):
    return f(9) if f else 9


def plus(y):
    return lambda x: int(x + y)


def minus(y):
    return lambda x: int(x - y)


def times(y):
    return lambda x: int(x * y)


def divided_by(y):
    return lambda x: int(x / y)
