import time
import sys
hour=0
minute=0
second=0

while True:
    print(str(hour)+":"+str(minute)+":"+str(second))
    time.sleep(1)
    second=second+1
    if second==60:
        minute=minute+1
        second=0
    if minute==60:
        hour=hour+1
        minute=0
    if hour==25:
        hour=0