import functools


class Vector:
    def __init__(self, list):
        self.list = list

    def __add__(self, other):
        if len(self.list) != len(other.list):
            raise TypeError()
        return Vector([x + y for (x, y) in zip(self.list, other.list)])

    def __sub__(self, other):
        if len(self.list) != len(other.list):
            raise TypeError()
        return Vector([x - y for (x, y) in zip(self.list, other.list)])

    def __mul__(self, other):
        if isinstance(other, Vector):
            if len(self.list) != len(other.list):
                raise TypeError()
            return sum([x * y for (x, y) in zip(self.list, other.list)])

        return [x * other for x in self.list]

    def __rmul__(self, other):
        return self.__mul__(other)

    def __eq__(self, other):
        return functools.reduce(
            (lambda a, b: a and b),
            [x == y for (x, y) in zip(self.list, other.list)]
        )

    def __len__(self):
        return len(self.list)

    def __getitem__(self, i):
        return self.list[i]

    def __setitem__(self, key, value):
        self.list[key] = value

    def __str__(self):
        return '[' + ', '.join(map(str, self.list)) + ']'

    def __iadd__(self, other):
        if len(self.list) != len(other.list):
            raise TypeError()
        self.list = [x + y for (x, y) in zip(self.list, other.list)]
        return self

    def __imul__(self, other):
        if isinstance(other, Vector):
            if len(self.list) != len(other.list):
                raise TypeError()
            return sum([x * y for (x, y) in zip(self.list, other.list)])

        self.list = [x * other for x in self.list]
        return self

    def __isub__(self, other):
        if len(self.list) != len(other.list):
            raise TypeError()
        self.list = [x - y for (x, y) in zip(self.list, other.list)]
        return self

    def __abs__(self):
        return sum([x ** 2 for x in self.list]) ** 0.5