George woke up and saw the current time *s* on the digital clock. Besides, George knows that he has slept for time *t*. 

Help George! Write a program that will, given time *s* and *t*, determine the time *p* when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample).
The first line contains current time *s* as a string in the format "hh:mm". The second line contains time *t* in the format "hh:mm" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, 00 ≤ *hh* ≤ 23, 00 ≤ *mm* ≤ 59.
def time(h,m):
  if h < 0:
    h += 24
  if h <10:
    h = f'{0}{h}'
  if m < 10:
    m = f'{0}{m}'
  return f'{h}:{m}'

def solve(s, t):
  sh,sm = map(int, s.split(':'))
  th,tm = map(int,t.split(':'))
  tot_s = sh*60+sm
  tot_t = th*60+tm
  res = tot_s - tot_t
  return time(res//60, res%60)

    

  
def main() :
  # n = int(input())
  # arr = list(map(int, input().split(' ')))
  # arr = []
  # for _ in range(4):
    # i = input()
    # arr.append(i)
  s = input()
  t = input()
  print(solve(s,t))
main()
