class Calculator:

    def __init__(self, list):
        self.list = list
        self.result = 0

    def sum(self):
        while self.list:
            self.result += self.list.pop()
        return self.result

b754f336303078b0c0c445845df8cf49d7a3587d
<mask token>

class Calculator:
    <mask token>
    <mask token>

class Calculator:
    <mask token>

    def sum(self):
        while self.list:
            self.result += self.list.pop()
        return self.result

class Calculator:

    def __init__(self, list):
        self.list = list
        self.result = 0

    def sum(self):
        while self.list:
            self.result += self.list.pop()
        return self.result
