Time + 15 Minutes

start_hour = int(input())
start_minutes = int(input())

time_In_minutes = start_hour*60+start_minutes
time_plus_15 = time_In_minutes + 15

finish_hour = time_plus_15 // 60
finish_minuts = time_plus_15 % 60

if finish_hour >= 24:
    finish_hour -=24
if finish_minuts <10:
    print(f"{finish_hour}:0{finish_minuts}")
else:
    print(f"{finish_hour}:{finish_minuts}")