#task 1
class Time:
  def __init__(self,start,end):
    self.__startTime = start 
    self.__endTime = end

  def getStart(self):
    return self.__startTime

  def getEnd(self):
    return self.__endTime

#task 2
activityTimes = []

for i in range(5):
  start = int(input("Enter start time"))
  end = int(input("Enter end time:"))

  while start<0 or end>60:
    print("Start must be 0 or greater, end must be less than 60")
    start = int(input("Enter start time"))
    end = int(input("Enter end time:")) 

  activityTimes.append(Time(start,end))


#task 3
def getTotalTime():
  total = 0
  print(len(activityTimes))
  for i in range(len(activityTimes)):
    activity = activityTimes[i].getEnd() - activityTimes[i].getStart()
    total = total + activity

  return total

#call the function and print the returned value
print(getTotalTime())