写的一个程序，内容是：已知2条地铁线路，其中A为环线，B为东西向线路，线路都是双向的。经过的站点名分别如下，两条线交叉的换乘点用T1、T2表示。编写程序，任意输入两个站点名称，输出乘坐地铁最少需要经过的车站数量（含输入的起点和终点，换乘站点只计算一次）-Known two subway lines, where A is the loop, B east-west lines, lines are bidirectional. After the domain name are as follows, two lines cross transfer points with T1, T2 represents. Programming, any input both the site name, the output station subway ride requires a minimum number of passes (including the start and end input, transfer the site only once)