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 = s % 60
        return Time(m, s)

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

t1 = Time(5, 50)
print(t1) # 5:50
t2 = Time(3, 20)
print(t2) # 3:20
t3 = t1 + t2
print(t3)  # 9:10

li = [Time(5, 50), Time(3, 20)]
print(li)