n = int(input())
hour=0
time=0

for i in range(n):
    data = input().split()
    bed = list(map(int,data[0].split(":")))
    wake = list(map(int,data[1].split(":")))
    
    if wake[0]>=bed[0]:
        hour = wake[0] - bed[0]
    else:
        hour = 24-bed[0] + wake[0]
    
    if wake[1]>=bed[1]:
        min = wake[1]-bed[1]
    else:
        min = 60-bed[1] + wake[1]
        hour -= 1
    
    if hour<0:
        hour += 24
        
    time += hour*60 + min
    print(hour,min)
    
print(time)