A. Lily Pads
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Unfortunately, the sample output is not "NO". If that were the case, it would be impossible to AC at all!
– Waymo, It's Time to Submit

Two frogs, Thomas and Waymo, are attempting to cross a pond.

Currently, they are both at the starting shore of the pond. In the pond, there are $$$N$$$ rows of unoccupied lily pads. In each row, there are two lily pads, a left lily pad and a right lily pad. One of them is afloat, and one of them is underwater. Also, each lily pad can hold at most one frog.

A frog may jump from the starting shore to an unoccupied and afloat lily pad in the first row, or from a lily pad in one row to an unoccupied and afloat lily pad in the next row, or from a lily pad in the last row to the ending shore.

When a frog jumps from a lily pad, that lily pad goes underwater, and the other lily pad in its row goes afloat. If a frog jumps from the right lily pad in a row, the right lily pad will go underwater, and the left lily pad will go afloat, and vice versa. Also, the frogs are polite. Thus, when one frog is mid-jump, the other frog will not jump.

Thomas and Waymo will jump in any order, obeying the above rules, until they both have made it to the ending shore. When a frog lands on a lily pad on the right, it gains a point. What is the maximum number of points total that Waymo and Thomas can gain?

Input

The first line contains $$$N$$$ ($$$1 \le N \le 100$$$), the number of rows of lily pads.

The second line contains a string $$$s$$$ with characters $$$s_1s_2 \dots s_n$$$. If $$$s_i = L$$$, the left lily pad on the $$$i$$$-th row is currently afloat, and if $$$s_i = R$$$, the right lily pad is currently afloat.

—

Tests in subtasks are numbered from $$$1−20$$$ with samples skipped. Each test is worth $$$\frac{100}{20}=5$$$ points.

Tests $$$1-20$$$ satisfy no additional constraints.

Output

Output the maximum number of points that Waymo and Thomas can earn.

Example
Input
1
R
Output
1
Note

A possible jumping order which gains 1 point is:

- Thomas jumps to row $$$1$$$. Thomas lands on the afloat right lily pad and gains a point.

- Thomas jumps to the ending shore. Now, in row $$$1$$$, the right lily pad is underwater, and the left lily pad is afloat.

- Waymo jumps to row $$$1$$$. Waymo lands on the now afloat left lily pad but does not gain a point.

- Waymo jumps to the ending shore. Now, in row $$$1$$$, the left lily pad is underwater, and the right lily pad is afloat.

After both frogs have reached the ending shore, they have gained $$$1$$$ point total.

—

Problem Idea: Alex_C

Problem Preparation: jay_jayjay

Occurrences: Novice A, Advanced A