Problem Statement

Takahashi has a piano with $100$ keys arranged in a row. The $i$-th key from the left is called key $i$.

He will play music by pressing $N$ keys one by one. For the $i$-th press, he will press key $A_i$, using his left hand if $S_i=$ L, and his right hand if $S_i=$ R.

Before starting to play, he can place both of his hands on any keys he likes, and his fatigue level at this point is 0. During the performance, if he moves one hand from key $x$ to key $y$, the fatigue level increases by $|y-x|$ (conversely, the fatigue level does not increase for any reason other than moving hands). To press a certain key with a hand, that hand must be placed on that key.

Find the minimum possible fatigue level at the end of the performance.

Constraints

• $1 \leq N \leq 100$
• $1 \leq A_i \leq 100$
• $N$ and $A_i$ are integers.
• $S_i$ is L or R.

Sample Input 1Copy

4
3 L
6 R
9 L
1 R

Sample Output 1Copy

11

For example, the performance can be done as follows:

• Initially, place the left hand on key $3$ and the right hand on key $6$.
• Press key $3$ with the left hand.
• Press key $6$ with the right hand.
• Move the left hand from key $3$ to key $9$. The fatigue level increases by $|9-3| = 6$.
• Move the right hand from key $6$ to key $1$. The fatigue level increases by $|1-6| = 5$.
• Press key $9$ with the left hand.
• Press key $1$ with the right hand.

In this case, the fatigue level at the end of the performance is $6+5 = 11$, which is the minimum possible.

Sample Input 2Copy

3
2 L
2 L
100 L

Sample Output 2Copy

98

Sample Input 3Copy

8
22 L
75 L
26 R
45 R
72 R
81 R
47 L
29 R

Sample Output 3Copy

188