Let's call a string a phone number if it has length 11 and fits the pattern "8xxxxxxxxxx", where each "x" is replaced by a digit.

For example, "80123456789" and "80000000000" are phone numbers, while "8012345678" and "79000000000" are not.

You have $\mathrm{n\; n cards\; with\; digits,\; and\; you\; want\; to\; use\; them\; to\; make\; as\; many\; phone\; numbers\; as\; possible.\; Each\; card\; must\; be\; used\; in\; at\; most\; one\; phone\; number,\; and\; you\; don\text{'}t\; have\; to\; use\; all\; cards.\; The\; phone\; numbers\; do\; not\; necessarily\; have\; to\; be\; distinct.}$

The first line contains an integer $\mathrm{nn —\; the\; number\; of\; cards\; with\; digits\; that\; you\; have\; (1\le n\le 1001\le n\le 100).}$

The second line contains a string of $\mathrm{nn digits\; (characters\; "0",\; "1",\; ...,\; "9") s1,s2,\dots ,sns1,s2,\dots ,sn.\; The\; string\; will\; not\; contain\; any\; other\; characters,\; such\; as\; leading\; or\; trailing\; spaces.}$

If at least one phone number can be made from these cards, output the maximum number of phone numbers that can be made. Otherwise, output 0.

In the first example, one phone number, "8000000000", can be made from these cards.

In the second example, you can make two phone numbers from the cards, for example, "80123456789" and "80123456789".

In the third example you can't make any phone number from the given cards.

题目意思：给你长度为n个数字字符串，求出能够组合成多少个电话号码。每一个数字都只能使用一次，电话号必须是8开头，长度为11。

解题思路：数字字符串的长度和8的数量决定了能构成的电话号码的个数。