Contest Duration: - (local time) (100 minutes) Back to Home
C - Attention /

Time Limit: 2 sec / Memory Limit: 1024 MB

問題文

N 人の人が東西方向に一列に並んでいます。 それぞれの人は、東または西を向いています。 誰がどの方向を向いているかは長さ N の文字列 S によって与えられます。 西から i 番目に並んでいる人は、S_i = E なら東を、S_i = W なら西を向いています。

あなたは、N 人のうち誰か 1 人をリーダーとして任命します。 そして、リーダー以外の全員に、リーダーの方向を向くように命令します。 このとき、リーダーはどちらの方向を向いていても構いません。

制約

• 2 \leq N \leq 3 \times 10^5
• |S| = N
• S_iE または W である

入力

N
S


入力例 1

5
WEEWW


出力例 1

1


入力例 2

12
WEWEWEEEWWWE


出力例 2

4


入力例 3

8
WWWWWEEE


出力例 3

3


Score : 300 points

Problem Statement

There are N people standing in a row from west to east. Each person is facing east or west. The directions of the people is given as a string S of length N. The i-th person from the west is facing east if S_i = E, and west if S_i = W.

You will appoint one of the N people as the leader, then command the rest of them to face in the direction of the leader. Here, we do not care which direction the leader is facing.

The people in the row hate to change their directions, so you would like to select the leader so that the number of people who have to change their directions is minimized. Find the minimum number of people who have to change their directions.

Constraints

• 2 \leq N \leq 3 \times 10^5
• |S| = N
• S_i is E or W.

Input

Input is given from Standard Input in the following format:

N
S


Output

Print the minimum number of people who have to change their directions.

Sample Input 1

5
WEEWW


Sample Output 1

1


Assume that we appoint the third person from the west as the leader. Then, the first person from the west needs to face east and has to turn around. The other people do not need to change their directions, so the number of people who have to change their directions is 1 in this case. It is not possible to have 0 people who have to change their directions, so the answer is 1.

Sample Input 2

12
WEWEWEEEWWWE


Sample Output 2

4


Sample Input 3

8
WWWWWEEE


Sample Output 3

3