公交车乘客

s = int(raw_input())L1 = []for i in range(s):    L1.append(raw_input())L2 = []for i in range(s):    L2.append(int(L1[i][2])-int(L1[i][0]))max = 0sum = 0 for i in range(len(L2)):    sum += L2[i]    if sum > max:        max = sum    if sum < 0:        sum = 0print max

**输入：第一行读入一个整数n(1<=n<=100)，表示有n个站点
接下来n行，每行两个数值，分别表示在第i个站点下车人数和上车人数，输出：每组输出车上最多的乘客数目**