Sum Seconds

import math

timeFirst = int(input())
timeSec = int(input())
timeThird = int(input())

totalTime = timeFirst + timeSec + timeThird

minutes = totalTime // 60
seconds = totalTime % 60

minutes = math.floor(minutes)

if seconds < 10:
    print(f"{minutes}:0{seconds}")
else:
    print(f"{minutes}:{seconds}")