class Time:
    def __init__(self, minutes, seconds):
        self.minutes = minutes
        self.seconds = seconds

    def __add__(self, other):
        m = self.minutes + other.minutes
        s = self.seconds + other.seconds
        m += s // 60
        s %= 60
        return Time(m, s)

    def __iadd__(self, other):
        m = self.minutes + other.minutes
        s = self.seconds + other.seconds
        m += s // 60
        s %= 60
        self.minutes = m
        self.seconds = s
        return self

    def info(self):
        return f'{self.minutes}:{self.seconds}'

t1 = Time(5, 50)
print(t1.info()) # 5:50
t2 = Time(3, 20)
print(t2.info()) # 3:20
print(id(t1))
t1 += t2
print(t1.info()) # 9:10
print(id(t1)) # id объекта не поменяется