Code Generator

Disha has a string $S$. In one second, Disha can choose a subsequence from $S$ that make the word “code” and remove it from the string. The process will be continued until she can't choose a subsequence that make the word.

In this problem, Good letter means [c,d,e,o]. And others letters are Bad.

Now, you have to find the maximum number of seconds Disha will work.

Input

The first line of the input contains a single integer $n$- the length of the string $s$.
Next line contains string $s$. the string consists of only lowercase English letters.

Constraints

Subtask 1 (10 points)

$1 \le n \le 5000$

Subtask 2 (30 points)

$1 \le n \le 500000$
Number of good letters $\leq 5000$

Subtask 3 (60 points)

$1 \le n \le 500000$

Output

Output the maximum number of seconds Disha will work.

Sample

Input	Output
8 codceode	2