判断火车票位置

a = input()
if 2 <= len(a) <= 3:   
    if a[0:-1].isdigit() == True and 1<=int(a[0:-1])<=17:     
        if a[-1] in ['a','f','A','F']:     
            print("窗口")
        elif a[-1] in ['c','d','C','D']:   
            print("过道")
        else:
            print("输入错误")
    else:
        print("输入错误")
else:
    print('输入错误')