#!/usr/bin/env python

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

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

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