from datetime import datetime
 
t1=input("Start time\n")
t2=input("End time\n")
fmt='%H:%M:%S'
t=str(datetime.strptime(t2,fmt)-datetime.strptime(t1,fmt))
 
h,m,s=map(int,t.split(':'))
 
print("Time in milliseconds is {}".format(int(3600000*h+60000*m+1000*s)))