P2338 [USACO14JAN] Bessie Slows Down S

Bessie the cow is competing in a cross-country skiing event at the winter Moolympic games. She starts out at a speed of 1 meter per second. However, as she becomes more tired over time, she begins to slow down. Each time Bessie slows down, her speed decreases: she moves at 1/2 meter per second after slowing down once, then 1/3 meter per second after slowing down twice, and so on. You are told when and where Bessie slows down, in terms of a series of events. An event like this: T 17 means that Bessie slows down at a specific time -- here, 17 seconds into the race. An event like this: D 10 means that Bessie slows down at a specific distance from the start -- in this case, 10 meters. Given a list of N such events (1

第一行：单个整数 $N$，$1\le N\le10000$。 第二行到第 $N+1$ 行：每行开头有一个大写字母，代表贝西的一个失误类型： - 如果是 `T`，接下来会有一个整数 $S$，表示在比赛开始后的第 $S$ 秒钟整发生了一次失误，$1\le S\le10^7$。 - 如果是 `D`，接下来会有一个整数 $X$，表示在距离起点 $X$ 米处发生了一次失误，$1\le X\le1000$。

单个整数：表示贝西需要多少秒才能滑到终点，如果精确的时间不是整数，则用四舍五入的方法向最接近的整数取整。

样例解释： 前 $10$ 秒，贝西的速度是每秒 $1$ 米，她滑了 $10$ 米。然后她遭遇了第一次失误，在接下来的 $20$ 秒内，她又滑了 $10$ 米。之后她遭遇了第二次失误，还剩下 $980$ 米，所以她共计花去 $10+20+2940=2970$ 秒才完成比赛。