line = [int(i) for i in input().split(":")]
hour = line[0]
minutes = line[1]

if minutes + 5 >= 60:
    min_after_nidone = (minutes + 5) % 10
    hour = hour + 1
else:
    min_after_nidone = minutes + 5

if hour == 24:
    hour = 0

formatted_hour = "%02d" % hour
formatted_min  = "%02d" % min_after_nidone
print(formatted_hour + ":" +  formatted_min)