Sum Seconds

firstPlayer = int(input())
secondPlayer = int(input())
thirdPlayer = int(input())

totalTimeInMin = (firstPlayer + secondPlayer + thirdPlayer)/60
totalTimeSeconds = (firstPlayer + secondPlayer + thirdPlayer) % 60

if totalTimeSeconds < 10:
    print(f"{int(totalTimeInMin)}:0{totalTimeSeconds}")
else:
    print(f"{int(totalTimeInMin)}:{totalTimeSeconds}")