Chef has a sequence of positive integers $A_1, A_2, \ldots, A_N$. He wants to choose some elements of this sequence (possibly none or all of them) and compute their MEX, i.e. the smallest positive integer which does not occur among the chosen elements. For example, the MEX of $[1, 2, 4]$ is $3$.
Help Chef find the largest number of elements of the sequence $A$ which he can choose such that their MEX is equal to $M$, or determine that it is impossible.

-----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 $M$.
- 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 maximum number of elements Chef can choose, or $-1$ if he cannot choose elements in such a way that their MEX is $M$.

-----Constraints-----
- $1 \le T \le 100$
- $2 \le M \le N \le 10^5$
- $1 \le A_i \le 10^9$ for each valid $i$
- the sum of $N$ over all test cases does not exceed $10^6$

-----Example Input-----
1
3 3
1 2 4

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

-----Explanation-----
Example case 1: The MEX of whole array is 3. Hence, we can choose all the elements.

```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 = 'from sys import stdin, stdout\nfrom collections import defaultdict as D\n\ntry:\n    for _ in range(int(input())):\n        n,m=[int(i) for i in stdin.readline().split()]\n        a=[int(i) for i in stdin.readline().split()]\n        d = D(lambda:0)\n        for i in a:\n            d[i] += 1 \n        \n        k = 1\n        for i in range(1, max(a) + 2):\n            if d[i] == 0:\n                k = i\n                break\n        \n        if k==m:\n            print(n)\n        elif k<m:\n            print(-1)\n        elif k>m:\n            print(n - d[m])\nexcept:\n    pass'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 13831