#include <bits/stdc++.h>
using namespace std;

// #define int long long
#define fi first
#define se second
#define endl '\n'
#define lc (u << 1)
#define rc (u << 1 | 1)
#define pb push_back
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;

/******************************************************************/
#define debug(x...)                  \
    do {                           \
        std::cout << #x << " -> "; \
        err(x);                    \
    } while (0)
 
void err() {
    std::cout << '\n';
}
 
template <class T, class... Ts>
void err(T arg, Ts ...args) {
    std::cout << arg << ' ';
    err(args...);
}

/*
assert(expression);  // 断言
string line;
getline(cin, line);
stringstram sline(line);  // string流
cout << unitbuf;  //所有输出操作后都会立即刷新缓冲区
*/
/******************************************************************/

const int INF = 0x3f3f3f3f;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
const long long One = 1LL;

int dir[4][2] = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};

struct node{
	int x, y, z;
	bool operator < (const node& a) const{
		return x < a.x;
	}
};

void solve(){
	int n, m;
	cin >> n >> m;
	vector<int> a(n);
	for (int i = 0; i < n; i ++)
		cin >> a[i];
	
	int ans = -1;
	for (int i = 1; i <= 1000 && i <= m; i ++){
		int res = 0;
		unordered_map<int, int> mp;
		for (int j = 0; j < n; j ++){
			if (a[j] == i){
				ans = max(ans, (int)mp.size() - i);
				mp.clear();
			}
			else{
				mp[a[j]] = 1;
			}
		}

		ans = max(ans, (int)mp.size() - i);
	}

	cout << ans << endl;

}

signed main(void){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(20);
	int t = 1;
	cin >> t;
	while (t --){
		solve();
	}
	
	return 0;
}
/*
input:

output:

*/