CF725B.Food on the Plane

A new airplane SuperPuperJet has an infinite number of rows, numbered with positive integers starting with 1 from cockpit to tail. There are six seats in each row, denoted with letters from 'a' to 'f'. Seats 'a', 'b' and 'c' are located to the left of an aisle (if one looks in the direction of the cockpit), while seats 'd', 'e' and 'f' are located to the right. Seats 'a' and 'f' are located near the windows, while seats 'c' and 'd' are located near the aisle.

It's lunch time and two flight attendants have just started to serve food. They move from the first rows to the tail, always maintaining a distance of two rows from each other because of the food trolley. Thus, at the beginning the first attendant serves row 1 while the second attendant serves row 3. When both rows are done they move one row forward: the first attendant serves row 2 while the second attendant serves row 4. Then they move three rows forward and the first attendant serves row 5 while the second attendant serves row 7. Then they move one row forward again and so on.

Flight attendants work with the same speed: it takes exactly 1 second to serve one passenger and 1 second to move one row forward. Each attendant first serves the passengers on the seats to the right of the aisle and then serves passengers on the seats to the left of the aisle (if one looks in the direction of the cockpit). Moreover, they always serve passengers in order from the window to the aisle. Thus, the first passenger to receive food in each row is located in seat 'f', and the last one — in seat 'c'. Assume that all seats are occupied.

Vasya has seat s in row n and wants to know how many seconds will pass before he gets his lunch.

一架新型飞机 SuperPuperJet 拥有无限多排座位，排号从机头向机尾方向用正整数编号，起始为 1。每排有六个座位，用字母 'a' 到 'f' 表示。若面向机头方向观察，则座位 'a'、'b' 和 'c' 位于过道左侧，座位 'd'、'e' 和 'f' 位于过道右侧。其中，座位 'a' 和 'f' 靠近舷窗，座位 'c' 和 'd' 靠近过道。

现在是午餐时间，两名空乘人员刚刚开始送餐。他们从最前排向机尾方向行进，因餐车限制，两人始终保持相距两排的距离。因此，初始时刻，第一名空乘人员服务第 1 排，第二名空乘人员服务第 3 排；当这两排全部服务完毕后，两人各自向前移动一排：第一名空乘人员服务第 2 排，第二名空乘人员服务第 4 排；接着，两人再同时向前移动三排：第一名空乘人员服务第 5 排，第二名空乘人员服务第 7 排；然后再次各自向前移动一排，依此类推。

两名空乘人员工作速度相同：为每位乘客送餐恰好耗时 1 秒，向前移动一排也恰好耗时 1 秒。每位空乘人员均先服务过道右侧的乘客，再服务过道左侧的乘客（面向机头方向观察）；且在每一侧内，始终按由舷窗至过道的顺序服务。因此，每排中第一位获得餐食的乘客位于座位 'f'，最后一位位于座位 'c'。假设所有座位均已被占用。

瓦夏的座位号为 s，所在排号为 n，他想知道距离自己收到午餐还有多少秒。

The only line of input contains a description of Vasya's seat in the format ns, where n (1 ≤ n ≤ 1018) is the index of the row and s is the seat in this row, denoted as letter from 'a' to 'f'. The index of the row and the seat are not separated by a space.

输入仅有一行，包含瓦西娅座位的描述，格式为 ns，其中 n（1 ≤ n ≤ 10¹⁸）表示排号，s 表示该排中的座位号，用字母 'a' 到 'f' 表示。排号与座位号之间不用空格分隔。

Print one integer — the number of seconds Vasya has to wait until he gets his lunch.

输出一个整数——Vasya 需要等待多少秒才能拿到他的午餐。

In the first sample, the first flight attendant serves Vasya first, so Vasya gets his lunch after 1 second.

In the second sample, the flight attendants will spend 6 seconds to serve everyone in the rows 1 and 3, then they will move one row forward in 1 second. As they first serve seats located to the right of the aisle in order from window to aisle, Vasya has to wait 3 more seconds. The total is 6 + 1 + 3 = 10.

在第一个样例中，第一位乘务员最先为瓦西亚服务，因此瓦西亚在 1 秒后得到他的午餐。

在第二个样例中，乘务员需要 6 秒来为第 1 行和第 3 行的所有乘客提供服务，然后他们向前移动一行需 1 秒。由于乘务员首先按从靠窗到过道的顺序为位于过道右侧的座位提供服务，瓦西亚还需等待 3 秒。总时间为 $6 + 1 + 3 = 10$。