本弱鸡已经触发的错误姿势：
freoprn("railway.in","r",stdin);
freopen("railway.cpp","r",stdin);
freopen("railway.out","W",stdout);
freopen("railway.in","r",stdout);
freopen("railway.our","w",stdout);//石队长触发的
freopen("railway,out","w",stdout);
freopen("edd.out","w",stdout);//本来叫egg
//freopen("egg.out","w",stdout);