Score : 300 points
There are N Reversi pieces arranged in a row. (A Reversi piece is a disc with a black side and a white side.)
The state of each piece is represented by a string S of length N.
If S_i=B
, the i-th piece from the left is showing black;
If S_i=W
, the i-th piece from the left is showing white.
Consider performing the following operation:
Find the maximum possible number of times this operation can be performed.
B
or W
Input is given from Standard Input in the following format:
S
Print the maximum possible number of times the operation can be performed.
BBW
2
The operation can be performed twice, as follows:
BWBWBW
6