Finally, a COVID vaccine is out on the market and the Chefland government has asked you to form a plan to distribute it to the public as soon as possible. There are a total of $N$ people with ages $a_1, a_2, \ldots, a_N$.
There is only one hospital where vaccination is done and it is only possible to vaccinate up to $D$ people per day. Anyone whose age is $\ge 80$ or $\le 9$ is considered to be at risk. On each day, you may not vaccinate both a person who is at risk and a person who is not at risk. Find the smallest number of days needed to vaccinate everyone.

-----Input-----
- The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
- The first line of each test case contains two space-separated integers $N$ and $D$.
- The second line contains $N$ space-separated integers $a_1, a_2, \ldots, a_N$.

-----Output-----
For each test case, print a single line containing one integer ― the smallest required number of days.

-----Constraints-----
- $1 \le T \le 10$
- $1 \le N \le 10^4$
- $1 \le D \le 10^5$
- $1 \le a_i \le 100$ for each valid $i$

-----Subtasks-----
Subtask #1 (100 points): original constraints

-----Example Input-----
2
10 1
10 20 30 40 50 60 90 80 100 1
5 2
9 80 27 72 79

-----Example Output-----
10
3

-----Explanation-----
Example case 1: We do not need to worry about how the people are grouped, since only one person can be vaccinated in a single day. We require as many days as there are people.
Example case 2: There are two people at risk and three people who are not at risk. One optimal strategy is to vaccinate the two people at risk on day $1$ and the remaining three on the next $2$ days.

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

ns = {"__name__": "__main__"}
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 't=int(input())\ni=0\nwhile i<t:\n n,d=input().split()\n n=int(n)\n d=int(d)\n a=[]\n days=0\n a=input().split()\n j=0\n risk=0\n while j<n:\n  x=int(a[j])\n  if x>=80 or x<=9:\n   risk+=1\n  j+=1\n nrisk=n-risk\n if risk%d==0:\n  days=int(risk/d)\n else:\n  days=int(risk//d)+1\n if nrisk%d==0:\n  days+=int(nrisk/d)\n else:\n  days+=int(nrisk//d)+1\n print(days)\n i+=1'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 13285