Lose it!

2000ms

262144K

Description:

You are given an array $$$a$$$ consisting of $$$n$$$ integers. Each $$$a_i$$$ is one of the six following numbers: $$$4, 8, 15, 16, 23, 42$$$.

Your task is to remove the minimum number of elements to make this array good.

An array of length $$$k$$$ is called good if $$$k$$$ is divisible by $$$6$$$ and it is possible to split it into $$$\frac{k}{6}$$$ subsequences $$$4, 8, 15, 16, 23, 42$$$.

Examples of good arrays:

$$$[4, 8, 15, 16, 23, 42]$$$ (the whole array is a required sequence);
$$$[4, 8, 4, 15, 16, 8, 23, 15, 16, 42, 23, 42]$$$ (the first sequence is formed from first, second, fourth, fifth, seventh and tenth elements and the second one is formed from remaining elements);
$$$[]$$$ (the empty array is good).

Examples of bad arrays:

$$$[4, 8, 15, 16, 42, 23]$$$ (the order of elements should be exactly $$$4, 8, 15, 16, 23, 42$$$);
$$$[4, 8, 15, 16, 23, 42, 4]$$$ (the length of the array is not divisible by $$$6$$$);
$$$[4, 8, 15, 16, 23, 42, 4, 8, 15, 16, 23, 23]$$$ (the first sequence can be formed from first six elements but the remaining array cannot form the required sequence).

Input:

The first line of the input contains one integer $$$n$$$ ($$$1 \le n \le 5 \cdot 10^5$$$) — the number of elements in $$$a$$$.

The second line of the input contains $$$n$$$ integers $$$a_1, a_2, \dots, a_n$$$ (each $$$a_i$$$ is one of the following numbers: $$$4, 8, 15, 16, 23, 42$$$), where $$$a_i$$$ is the $$$i$$$-th element of $$$a$$$.

Output:

Print one integer — the minimum number of elements you have to remove to obtain a good array.

Sample Input:

5
4 8 15 16 23

Sample Output:

Sample Input:

12
4 8 4 15 16 8 23 15 16 42 23 42

Sample Output:

Sample Input:

15
4 8 4 8 15 16 8 16 23 15 16 4 42 23 42

Sample Output:

Informação

Provedor Codeforces

Código CF1176C