result = lambda n: [n // 10, 'fail'][n < 70]

def letter(str):
    result = []
    words = [x for x in str.lower().strip().split() if x]
    mx = len(max(words, key=len)) if words else 0
    starts = set(x[:i] for x in words for i in range(1, mx+1))
    for s in starts:
        matching = [word for word in words if word.startswith(s)]
        if len(matching) == len(s):
            result += matching
    return sorted(result)

days = lambda y, m, d: sum(([31, [28, 29][all([not y % 4, (y % 100 or not y % 400)])]] + [31, 30, 31, 30, 31] * 2)[:m - 1]) + d

spawn_to_range = lambda a, v, r: a[:a.index(v)] + [v] * r + a[a.index(v) + 1:] if v in a else []

def spawn_to_range(a, v, r): i = a.index(v); return a[:i] + [v] * r + a[i + 1:]

foo = lambda a, b : list(set(a) - set(b))

def sort(x): z=lambda y: sorted(filter(y, x)); return ''.join(z(str.isalpha) + z(str.isdigit))

def assert_equal(*args):
    assert len(set(args)) == 1

    

#!/usr/bin/env python3
"""
Debugging: FixDatTrash # 2
"""

# constant:
PI = 3.1415926535897


class Calculator:
    """A calculator class."""

    def __init__(self, num):
        """Initialize attributes."""
        self.num = num

    def calculate_power(self, exp, base=None):
        """
        Calculates power of self.num.
        parameter `exp` is the exponent.
        parameter `base` is an optional argument to override self.num with.
        """
        return (base or self.num) ** exp

    def calculate_square_root(self):
        """Calculates square root of self.num or any other real number."""
        return self.calculate_power(0.5)

    def calculate_cube_root(self):
        """Calculates cube root of self.num or any other real number."""
        return self.calculate_power(1 / 3)

    def calculate_circumference(self, base=None):
        """
        Calculates circumference of circle.
        self.num is the diameter of the circle.
        """
        return PI * (base or self.num)
    
    def calculate_circle_area(self):
        """
        Calculates area of circle.
        self.num is the radius of the circle.
        A=πr2
        """
        radius_squared = self.calculate_power(2)
        return self.calculate_circumference(radius_squared)
    

is_armstrong = lambda n: n == sum(d ** len(str(n)) for d in [(n // max(10 ** i, 1)) % 10 for i in range(len(str(n)))])

find_multiples = lambda n: sum([i, 0][all([i % 4, i % 6])] for i in range(n))

"H".__mul__

fruit_colours = {
    "Red": ("Apple", "Raspberry", "Strawberry"),
    "Orange": ("Orange",),
    "Yellow": ("Banana", "Lemon", "Pineapple"),
    "Green": ("Avocado", "Lime", "Melon", "Pear"),
    "Blue":  ("Blueberry", "Huckleberry"),
    "Purple": ("Plum", "Grape", "Maquiberry")
}

colour_of_fruit = lambda fruit: next((colour for colour, fruits in fruit_colours.items() if fruit in fruits), "Not a fruit!")

hello_message = lambda this=__import__("this"), s=lambda this: ''.join([this.d[x] if x.isalpha() else x for x in this.s]): ''.join([s(this)[x] for x in [1, 2, 42, 42, 8, 3, 512, 8, 30, 42, 163, 855]]).title()

FindTRex = lambda lst: type("FindTRex", tuple(), {"lst" : lst, "find_trex" : lambda : "tyrannosaurus" in lst})