+ محدودیت زمان: ۱ ثانیه + محدودیت حافظه: ۲۵۶ مگابایت ---------- Maryam, a famous mathematician, recently has bought an old vintage car. This car uses a combustion engine to generate the power needed to move the car. Inside the engine, there are $n$ cylinders of length $m$ and inside each cylinder, there is a piston constantly moving up and down. All pistons move independently and at the same speed. At any given time, the position of a piston inside a cylinder can be shown with an integer from $0$ to $m$, which also describes the area of the cylinder occupied by the piston. A piston instantly changes its direction when it reaches the top (position $m$) or bottom (position $0$) of its cylinder. Maryam managed to determine the position and direction of all the pistons at a specific time. Now she is curious about the maximum total area occupied by all the pistons. Help Maryam find out this value # ورودی The first line of input contains two integers $n$ and $m$, describing the number of pistons and the length of cylinders, respectively. Each of the next $n$ lines describe the position and direction of a single piston. The $(i + 1)^{th}$ line of the input contains an integer $p_i$ and a character $d_i$ , the initial position of the $i^{th}$ piston and its direction (Up or Down), respectively. $$1 \leq n \leq 10^5$$ $$1 \leq m \leq 10^6$$ $$0 \leq p_i \leq m$$ $$d_i \in \{ U, D \}$$ # خروجی Print a single integer, the maximum total area occupied by all the pistons. # مثال‌ها ### ورودی نمونه ۱ ``` 2 5 2 U 5 D ``` ### خروجی نمونه ۱ ``` 7 ``` ### ورودی نمونه ۲ ``` 4 6 0 U 0 D 6 U 3 U ``` ### خروجی نمونه ۲ ``` 15 ```