Codeforces Round 246 (Div. 2)
A
Choosing Teams
Codeforces
800
原题
←B →
翻译中…

The Saratov State University Olympiad Programmers Training Center (SSU OPTC) has $*n*$ students. For each student you know the number of times he/she has participated in the ACM ICPC world programming championship. According to the ACM ICPC rules, each person can participate in the world championship at most 5 times.

翻译中…

The head of the SSU OPTC is recently gathering teams to participate in the world championship. Each team must consist of exactly three people, at that, any person cannot be a member of two or more teams. What maximum number of teams can the head make if he wants each team to participate in the world championship with the same members at least $*k*$ times?

翻译中…

Input

翻译中…

The first line contains two integers, $*n*$ and $*k*$ $(1 ≤ *n* ≤ 2000; 1 ≤ *k* ≤ 5)$. The next line contains $*n*$ integers: $*y*_{1}, *y*_{2}, ..., *y*_{*n*}$ $(0 ≤ *y*_{*i*} ≤ 5)$, where $*y*_{*i*}$ shows the number of times the $*i*$-th person participated in the ACM ICPC world championship.

翻译中…

Output

翻译中…

Print a single number — the answer to the problem.

翻译中…

Note

翻译中…

In the first sample only one team could be made: the first, the fourth and the fifth participants.

翻译中…

In the second sample no teams could be created.

翻译中…

In the third sample two teams could be created. Any partition into two teams fits.

翻译中…

样例

Input #1
5 2
0 4 5 1 0
Output #1
1
InputCopy OutputCopy
Input #2
6 4
0 1 2 3 4 5
Output #2
0
InputCopy OutputCopy
Input #3
6 5
0 0 0 0 0 0
Output #3
2
InputCopy OutputCopy
题目信息
题号
432A
时间限制
1 s
内存限制
256 MB
标签
贪心
模拟
排序

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。