times.py

from sys import argv

class time(object):
  def __init__(self,time):
    self.h=time[0]
    self.m=time[1]
    self.s=time[2]
  def addTime(self,other):
    self.m+=(self.s+other.s)//60
    self.s=(self.s+other.s)%60
    self.h+=(self.m+other.m)//60
    self.m=(self.m+other.m)%60
    self.h+=other.h
  def __str__(self): #string representation
    return "%d:%d:%d" % (self.h,self.m,self.s)

def strToTime(str):
  str=str.split(":")
  for a in range(0,len(str)):
    str[a]=int(str[a])
  return str

name, t1, t2 = argv

time1=time(strToTime(t1))
time2=time(strToTime(t2))
time1.addTime(time2)
print(time1)