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.
#Program George and Sleep

def main():
    wake = input()
    sleep = input()
    time1 = [int(sleep[:2]),int(sleep[3:])]
    time2 = [int(wake[:2]),int(wake[3:])]
    if time2[0] > time1[0]:
        total = time2[0]-time1[0],time2[1]-time1[1]
        if total[1]<0:
            total = total[0]-1,60+total[1]
    elif time2[0] == time1[0]:
        total = time2[0]-time1[0],time2[1]-time1[1]
        if total[1]<0:
            total = 23,60+total[1]
    elif time2[0] < time1[0]:
        total = 24+(time2[0]-time1[0]),time2[1]-time1[1]
        if total[1]<0:
            total = total[0]-1,60+total[1]
    output = []
    for x in range(len(total)):
        if total[x]<10:
            output.append("0"+str(total[x]))
        else:
            output.append(str(total[x]))
    print("{}:{}".format(output[0],output[1]))
main()
 		 			  	   	 	 	 	 	   	  	