Chef is given a sequence of prime numbers $A_1, A_2, \ldots, A_N$. This sequence has exactly $2^N$ subsequences. A subsequence of $A$ is good if it does not contain any two identical numbers; in particular, the empty sequence is good.
Chef has to find the number of good subsequences which contain at most $K$ numbers. Since he does not know much about subsequences, help him find the answer. This number could be very large, so compute it modulo $1,000,000,007$.

-----Input-----
- The first line of the input contains two space-separated integers $N$ and $K$.
- The second line contains $N$ space-separated integers $A_1, A_2, \ldots, A_N$.

-----Output-----
Print a single line containing one integer ― the number of good subsequences with size at most $K$, modulo $1,000,000,007$.

-----Constraints-----
- $1 \le K \le N \le 10^5$
- $2 \le A_i \le 8,000$ for each valid $i$

-----Subtasks-----
Subtask #1 (40 points): $A_1, A_2, \ldots, A_N$ are pairwise distinct
Subtask #2 (60 points): original constraints

-----Example Input-----
5 3
2 2 3 3 5

-----Example Output-----
18

-----Explanation-----
There is $1$ good subsequence with length $0$, $5$ good subsequences with length $1$, $8$ good subsequences with length $2$ and $4$ good subsequences with length $3$.

```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 = '# cook your dish here\nfrom sys import stdin, stdout\nimport math\nfrom itertools import permutations, combinations\nfrom collections import defaultdict\nfrom bisect import bisect_left \nfrom bisect import bisect_right\n \ndef L():\n return list(map(int, stdin.readline().split()))\n \ndef In():\n return list(map(int, stdin.readline().split()))\n \ndef I():\n return int(stdin.readline())\n \nP = 1000000007\ndef main():\n n, k = In()\n arr = L()\n ans = 0\n dict1 = {}\n \n \n for i in range(n):\n  if arr[i] in list(dict1.keys()):\n   dict1[arr[i]] += 1 \n  else:\n   dict1[arr[i]] = 1\n l1 = [-1]+list(dict1.keys())\n v = min(k, len(l1))\n dp = [[0 for i in range(v+1)]for i in range(len(l1))]\n dp[0][0] = 1\n for i in range(1, len(l1)):\n  dp[i][0] = 1\n  for j in range(1, v+1):\n   dp[i][j] = dp[i-1][j] + dp[i-1][j-1]*dict1[l1[i]]\n for i in range(v+1):\n  ans += dp[len(l1)-1][i]\n  ans = ans%P\n print(ans)\n  \n \n \ndef __starting_point():\n main()\n\n__starting_point()'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 15927