#!usr/bin/env python

import sys

current = sys.argv[1]
incremental = sys.argv[2]

if len(current) < 5:
    hours_current_in_minutes = int(current[0]) * 60
    minutes_current = int(current[2:4])
    total_current = minutes_current + hours_current_in_minutes
else:
    hours_current_in_minutes = int(current[0:2]) * 60
    minutes_current = int(current[3:5])
    total_current = minutes_current + hours_current_in_minutes

if len(incremental) < 5:
    hours_incremental_in_minutes = int(incremental[0]) * 60
    minutes_incremental = int(incremental[2:4])
    total_incremental = minutes_incremental + hours_incremental_in_minutes
else:
    hours_incremental_in_minutes = int(incremental[0:2]) * 60
    minutes_incremental = int(incremental[3:5])
    total_incremental = minutes_incremental + hours_incremental_in_minutes

total_overall_minutes = total_incremental + total_current
hours = total_overall_minutes / 60
minutes = total_overall_minutes % 60

#quick hotfixes below
if hours > 23:
    hours = hours - 24
if minutes < 10:
    minutes = "0" + str(minutes)
if minutes == 0:
    minutes = "00"

print str(hours) + ":" + str(minutes)