#!/usr/bin/env python

inval = input().split()
timediff = int(float(inval[2][3:])*10)*6 - 9*60

hour, minute = divmod(timediff,60)
minute = int(minute) + int(inval[1])
if minute >= 60:
    minute -= 60
    hour += 1
hour = int(hour) + int(inval[0])
if hour < 0:
    hour += 24
elif hour >= 24:
    hour -= 24

print('{:0>2}:{:0>2}'.format(hour,minute))