PROGRAMMING:Zhuzi (Ningbo primary school, 2012)
Weiwei's mother has a necklace made of a string of beads. The beads in this necklace can be up to three colors (red, blue and white, denoted by R, B and W respectively). One day, Weiwei wanted to take out some beads from her mother's necklace to play. Although her mother agreed, she put forward the following conditions:
(1) You can only choose one place to cut the necklace, and then take out the beads from the two ends of the broken necklace;
(2) If the color of the bead is the same as that of the first bead at each end, the bead can be removed continuously,
Until there is a bead with a different color from the first one at the end. If white beads are encountered, they can be seen as blue or white as needed
Red.
Weiwei has no special requirements for color, but she wants as many beads as possible.
For convenience, we number the beads in the necklace clockwise, as shown in figure-1 and figure-2
There are 11 beads in each necklace.
For figure-1, if the beads were cut between No. 1 and No. 2, a total of 2 beads could be obtained. And if
Cut between No. 6 and No. 7 beads, then the taste can get a total of 5 beads (3 red R on the left and 2 red R on the right)
Blue b), and 5 beads are also the maximum number of beads that Wei Wei can get from this necklace.
For the necklace in figure-2, if it is cut between No. 1 and No. 2 beads, a total of 4 beads can be taken (1
Take the No. 1 bead as blue, so 3 beads can be taken on the left and 1 bead can be taken on the right (b). And if you cut it between two and three,
Take 6 beads in total (take No. 1 bead as blue, so 4 blue B can be taken on the left and 2 red on the right)
Color R).
###Input format:
The input contains two lines. The first line is an integer n, which represents the total number of beads in the necklace. The second line is a string of characters of length N, which is composed of characters R, B and W. It indicates the arrangement of the beads of the necklace that start from a certain bead and unfold clockwise (of course, this bead is not necessarily the position where the taste actually needs to be cut).
###Output format:
The output contains only one value per line, which indicates the maximum number of beads that Wei Wei can get according to the rules of mother.
###Input sample 1:
```in
eleven
wbrrbbwbrbb
```
###Output sample 1:
```out
six
```
[explanation of input and output example 1] assume that the first character in the input string represents No. 1 bead
If No. 1 bead is regarded as blue, then cut between No. 2 and No. 3 beads, and the 6 beads obtained by Weiwei are numbered as
1、2、3、4、10、11； It can also be cut between No. 4 and No. 5 beads. If No. 7 bead is regarded as blue, the flavor can get beads
Their numbers are 3, 4, 5, 6, 7 and 8.
###Input sample 2:
```in
eleven
bbbbrbbbbrw
```
###Output sample 2:
```out
six
```
[data range]
For 60% of the data 3≤n≤100
For 100% data 3≤n≤350
answer：If there is no answer, please comment
(1) You can only choose one place to cut the necklace, and then take out the beads from the two ends of the broken necklace;
(2) If the color of the bead is the same as that of the first bead at each end, the bead can be removed continuously,
Until there is a bead with a different color from the first one at the end. If white beads are encountered, they can be seen as blue or white as needed
Red.
Weiwei has no special requirements for color, but she wants as many beads as possible.
For convenience, we number the beads in the necklace clockwise, as shown in figure-1 and figure-2
There are 11 beads in each necklace.
For figure-1, if the beads were cut between No. 1 and No. 2, a total of 2 beads could be obtained. And if
Cut between No. 6 and No. 7 beads, then the taste can get a total of 5 beads (3 red R on the left and 2 red R on the right)
Blue b), and 5 beads are also the maximum number of beads that Wei Wei can get from this necklace.
For the necklace in figure-2, if it is cut between No. 1 and No. 2 beads, a total of 4 beads can be taken (1
Take the No. 1 bead as blue, so 3 beads can be taken on the left and 1 bead can be taken on the right (b). And if you cut it between two and three,
Take 6 beads in total (take No. 1 bead as blue, so 4 blue B can be taken on the left and 2 red on the right)
Color R).
###Input format:
The input contains two lines. The first line is an integer n, which represents the total number of beads in the necklace. The second line is a string of characters of length N, which is composed of characters R, B and W. It indicates the arrangement of the beads of the necklace that start from a certain bead and unfold clockwise (of course, this bead is not necessarily the position where the taste actually needs to be cut).
###Output format:
The output contains only one value per line, which indicates the maximum number of beads that Wei Wei can get according to the rules of mother.
###Input sample 1:
```in
eleven
wbrrbbwbrbb
```
###Output sample 1:
```out
six
```
[explanation of input and output example 1] assume that the first character in the input string represents No. 1 bead
If No. 1 bead is regarded as blue, then cut between No. 2 and No. 3 beads, and the 6 beads obtained by Weiwei are numbered as
1、2、3、4、10、11； It can also be cut between No. 4 and No. 5 beads. If No. 7 bead is regarded as blue, the flavor can get beads
Their numbers are 3, 4, 5, 6, 7 and 8.
###Input sample 2:
```in
eleven
bbbbrbbbbrw
```
###Output sample 2:
```out
six
```
[data range]
For 60% of the data 3≤n≤100
For 100% data 3≤n≤350
answer：If there is no answer, please comment