#include<bits/stdc++.h>
using namespace std;
#define lowbit(x) (x) & (-x)
typedef long long ll;
const ll MAXN = 5e5 + 5;
ll Tex, n, m, a[MAXN], tr[MAXN], last[MAXN];
void add(ll x, ll k){
    while(x <= n){
        tr[x] += k;
        x += lowbit(x);
    }
}
ll sum(ll x){
    ll ret = 0;
    while(x){
        ret += tr[x];
        x -= lowbit(x);
    }
    return ret;
}
struct qst{
    ll l, r, cz;
};
bool operator < (qst xx, qst yy){
    if(xx.r == yy.r) return xx.l < yy.l;
    return xx.r < yy.r;
}
void AC(){
    cin >> n >> m;
    vector<qst> b;
    for(int i = 1; i <= n; i ++){
        cin >> a[i];
        b.push_back({last[a[i]] + 1, i - 1, a[i]});
        last[a[i]] = i;
    }
    for(int i = 1; i <= 800; i ++){
        b.push_back({last[i] + 1, n, i});
        last[i] = 0;
    }
    sort(b.begin(), b.end());
    ll dq_idx = 1, ans = -1;
    for(auto it : b){
        for(int i = dq_idx; i <= it.r; i ++){
            if(last[a[i]]) add(last[a[i]], -1);
            last[a[i]] = i;
            add(last[a[i]], 1); 
        }
        dq_idx = it.r + 1;
        ans = max(ans, sum(it.r) - sum(it.l - 1) - it.cz);
    }
    cout << ans << "\n";
    for(int i = 1; i <= n; i ++){
        add(i, -sum(i));
    }
    for(int i = 1; i <= 800; i ++){
        last[i] = 0;
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cin >> Tex;
    while(Tex --) AC();
    return 0;
}