#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define endl "\n"
#define fi first
#define se second
#define pb push_back
struct dd {
    ll l, r;
    ll num;
} xd[2002000];
ll idx = 0;
ll head[500500];
ll a[500500];
ll pos[500500];
ll js[500500];
bool cmp(dd a, dd b) {
    if (pos[a.l] == pos[b.l])
        return a.r < b.r;
    else
        return pos[a.l] < pos[b.l];
}
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    ll t = 1;
    cin >> t;
    while (t--) {
        ll n, m;
        cin >> n >> m;
        idx = 0;
        int sz = sqrt(n);
        for (int i = 1; i <= min(n, m); i++) head[i] = 0, js[i] = 0;
        for (int i = 1; i <= n; i++) {
            cin >> a[i], pos[i] = i / sz;
            if (i == 1) {
                head[a[i]] = 1;
                continue;
            }
            if (head[a[i]] + 1 > i - 1)
                head[a[i]] = i;
            else
                xd[++idx] = {head[a[i]] + 1, i - 1, a[i]};
            head[a[i]] = i;
        }
        // cout << "000" << endl;
        for (int i = 1; i <= min(n, m); i++) {
            if (head[i] != n) xd[++idx] = {head[i] + 1, n, i};
        }
        // for (int i = 1; i <= idx; i++) {
        //     cout << xd[i].l << " " << xd[i].r << " " << xd[i].num << endl;
        // }
        sort(xd + 1, xd + idx + 1, cmp);
        // cout << " 000 " << endl;
        int p1 = 1, p2 = 0;
        ll tot = 0;
        ll ans = -1;
        for (int i = 1; i <= idx; i++) {
            // cout << xd[i].l << " " << xd[i].r << endl;
            while (p2 < xd[i].r) {
                p2++;
                js[a[p2]]++;
                if (js[a[p2]] == 1) tot++;
            }
            while (p1 > xd[i].l) {
                p1--;
                js[a[p1]]++;
                if (js[a[p1]] == 1) tot++;
            }
            while (p2 > xd[i].r) {
                js[a[p2]]--;
                if (js[a[p2]] == 0) tot--;
                p2--;
            }
            while (p1 < xd[i].l) {
                js[a[p1]]--;
                if (js[a[p1]] == 0) tot--;
                p1++;
            }
            // cout << p1 << " " << p2 << endl;
            ans = max(ans, tot - xd[i].num);
        }
        cout << ans << endl;
    }
}
/*
2
5 4
1 2 2 3 4
5 10000
5 2 3 4 1
*/