t1 = input() t2 = input() s = int(input()) t11 = [] t22 = [] for i in range(3): t11.append(t1.split(":")[i]) t22.append(t2.split(":")[i])

tt1 = int(t11[0])*3600+int(t11[1])*60+int(t11[2]) tt2 = int(t22[0])*3600+int(t22[1])*60+int(t22[2]) sum = (tt2-tt1) * s print(sum)