#include <bits/stdc++.h>
#define int long long
#define endl '\n'
using namespace std;
const int N = 1000010;
typedef pair<int, int> PII;
int a[N];
int d[N * 4];
unordered_map<int, int> mp;
int n, m;
struct node
{
    int l, r, x;
};
bool cmp(node x, node y)
{
    return x.r < y.r;
}
void updown(int p)
{
    d[p] = d[p * 2] + d[p * 2 + 1];
}
void build(int s, int t, int p)
{
    if (s == t)
    {
        d[p] = 0;
        return;
    }
    int mid = (s + t) / 2;
    build(s, mid, p * 2), build(mid + 1, t, p * 2 + 1);
    return;
}
void chenge(int l, int c, int s, int t, int p)
{
    if (s == t)
    {
        d[p] = c;
        return;
    }
    int mid = (s + t) / 2;
    if (l <= mid)
    {
        chenge(l, c, s, mid, p * 2);
    }
    else
        chenge(l, c, mid + 1, t, p * 2 + 1);
    updown(p);
}
int cnt = 0;
int getsum(int l, int r, int s, int t, int p)
{
    if (s >= l && t <= r)
    {
        return d[p];
    }
    int mid = (s + t) / 2;
    int sum = 0;
    if (l <= mid)
    {
        sum += getsum(l, r, s, mid, p * 2);
    }
    if (r > mid)
    {
        sum += getsum(l, r, mid + 1, t, p * 2 + 1);
    }
    return sum;
}
void solve()
{
    cin >> n >> m;
    build(1, n, 1);
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    vector<node> q;
    q.push_back({0, -1, 0});
    for (int i = 1; i <= n; i++)
    {
        if (a[i] <= n + 1 && mp[a[i]] + 1 < i)
        {
            q.push_back({mp[a[i]] + 1, i - 1, a[i]});
        }
        mp[a[i]] = i;
    }
    for (int i = 1; i <= n; i++)
    {
        if (mp[a[i]] + 1 <= n)
        {
            q.push_back({mp[a[i]] + 1, n, i});
        }
        mp[a[i]] = i;
    }
    sort(q.begin(), q.end(), cmp);
    int now = 1;
    int ans = -1e18;
    for (int i = 1; i <= n; i++)
    {
        for (int j = now; j <= q[i].r; j++)
        {
            if (mp[a[j]])
            {
                // cout << a[j] << " " << mp[a[j]] << endl;
                chenge(mp[a[j]], 0, 1, n, 1);
            }
            chenge(j, 1, 1, n, 1);
            mp[a[j]] = j;
        }
        now = q[i].r + 1;
        // cout << now << endl;
        ans = max(ans, getsum(q[i].l, q[i].r, 1, n, 1) - q[i].x);
        // cout << res[q[i].id] << endl;
    }
    cout << ans << endl;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    cin >> T;
    while (T--)
    {
        solve();
    }
    return 0;
}