time_+15_minutes

hours = int(input())
minutes = int(input())
minutes = minutes + 15

if minutes > 59:
    minutes = minutes - 60
    hours = hours + 1

if hours > 23:
    hours = 0

if minutes > 9:
    print(f'{hours}:{minutes}')

else:
    print(f'{hours}:0{minutes}')