include <bits/stdc++.h>

using namespace std;

#define MAXN 500010

long long niz[MAXN];
vector<long long> pozicije[MAXN];
long long bit[MAXN];
long long last_visit[MAXN];
vector<pair<long long,long long>> query[MAXN];

void update(long long x,long long val,long long n)
{
    for (long long i=x;i<=n;i+=(i&(-i))) bit[i]+=val;
}

long long sol(long long x)
{
    long long br=0;
    for (long long i=x;i>=1;i-=(i&(-i))) br+=bit[i];
    return br;
}

void answer_queries(long long n)
{
    for (long long i=1;i<=n;i++) bit[i]=0;
    for (long long i=1;i<=n;i++) last_visit[i]=-1;
    long long ans=-LLONG_MAX;
    for (long long i=1;i<=n;i++)
    {
        if (last_visit[niz[i]]!=-1) update(last_visit[niz[i]],-1,n);
        last_visit[niz[i]]=i;update(i,1,n);
        long long s=query[i].size();
        for (long long j=0;j<s;j++)
        {
            long long l=query[i][j].first;
            long long mex=query[i][j].second;
            long long val=sol(i)-sol(l-1);
            ans=max(ans,val-mex);
        }
    }
    cout<<ans<<endl;
}

int main()
{
    ios_base::sync_with_stdio(false);
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    long long t;cin>>t;
    for (long long z=0;z<t;z++)
    {
        ///ZASTO OVO DAJE TLE JEBENI JEBAO VAS TL
        long long n,m;cin>>n>>m;
        for (long long i=1;i<=n;i++) cin>>niz[i];
        for (long long i=1;i<=n;i++) pozicije[niz[i]].clear();
        for (long long i=1;i<=n;i++) query[i].clear();
        for (long long i=1;i<=n;i++) pozicije[niz[i]].push_back(i);
        set<long long> sett;
        for (long long i=1;i<=n;i++) sett.insert(niz[i]);
        for (long long i=1;i<=n;i++)
        {
            if (sett.find(niz[i])==sett.end()) continue;
            long long s=pozicije[i].size();
            for (long long j=1;j<s;j++)
            {
                long long poz1=pozicije[i][j-1];
                long long poz2=pozicije[i][j];
                if (poz2-1>=poz1+1) query[poz2-1].push_back({poz1+1,i});
            }
            long long poz1=pozicije[i][0];
            if (poz1-1>=1) query[poz1-1].push_back({1,i});
            long long poz2=pozicije[i][s-1];
            if (n>=poz2+1) query[n].push_back({poz2+1,i});
        }
        long long mex_niza=1;
        for (auto p:sett)
        {
            if (p==mex_niza) mex_niza++;
        }
        query[n].push_back({1,mex_niza});
        answer_queries(n);
    }
}

answer.code:1:1: error: ‘include’ does not name a type
    1 | include <bits/stdc++.h>
      | ^~~~~~~
answer.code:8:1: error: ‘vector’ does not name a type
    8 | vector<long long> pozicije[MAXN];
      | ^~~~~~
answer.code:11:1: error: ‘vector’ does not name a type
   11 | vector<pair<long long,long long>> query[MAXN];
      | ^~~~~~
answer.code: In function ‘void answer_queries(long long int)’:
answer.code:29:20: error: ‘LLONG_MAX’ was not declared in this scope
   29 |     long long ans=-LLONG_MAX;
      |                    ^~~~~~~~~
answer.code:1:1: note: ‘LLONG_MAX’ is defined in header ‘<climits>’; did you forget to ‘#include <climits>’?
  +++ |+#include <climits>
    1 | include <bits/stdc++.h>
answer.code:34:21: error: ‘query’ was not declared in this scope
   34 |         long long s=query[i].size();
      |                     ^~~~~
answer.code:40:17: error: ‘max’ was not declared in this scope; did you mean ‘mex’?
   40 |             ans=max(ans,val-mex);
      |                 ^~~
      |                 mex
answer.code:43:5: error: ‘cout’ was not declared in this scope
   43 |     cout<<ans<<endl;
      |     ^~~~
answer.code:43:16: error: ‘endl’ was not declared in this scope
   43 |     cout<<ans<<endl;
      |                ^~~~
answer.code: In function ‘int main()’:
answer.code:48:5: error: ‘ios_base’ has not been declared
   48 |     ios_base::sync_with_stdio(false);
      |     ^~~~~~~~
answer.code:49:5: error: ‘ios’ has not been declared
   49 |     ios::sync_with_stdio(false);
      |     ^~~
answer.code:50:5: error: ‘cin’ was not declared in this scope
   50 |     cin.tie(0);
      |     ^~~
answer.code:51:5: error: ‘cout’ was not declared in this scope
   51 |     cout.tie(0);
      |     ^~~~
answer.code:58:38: error: ‘pozicije’ was not declared in this scope
   58 |         for (long long i=1;i<=n;i++) pozicije[niz[i]].clear();
      |                                      ^~~~~~~~
answer.code:59:38: error: ‘query’ was not declared in this scope
   59 |         for (long long i=1;i<=n;i++) query[i].clear();
      |                                      ^~~~~
answer.code:60:38: error: ‘pozicije’ was not declared in this scope
   60 |         for (long long i=1;i<=n;i++) pozicije[niz[i]].push_back(i);
      |                                      ^~~~~~~~
answer.code:61:9: error: ‘set’ was not declared in this scope
   61 |         set<long long> sett;
      |         ^~~
answer.code:61:13: error: expected primary-expression before ‘long’
   61 |         set<long long> sett;
      |             ^~~~
answer.code:62:38: error: ‘sett’ was not declared in this scope
   62 |         for (long long i=1;i<=n;i++) sett.insert(niz[i]);
      |                                      ^~~~
answer.code:65:17: error: ‘sett’ was not declared in this scope
   65 |             if (sett.find(niz[i])==sett.end()) continue;
      |                 ^~~~
answer.code:66:25: error: ‘pozicije’ was not declared in this scope
   66 |             long long s=pozicije[i].size();
      |                         ^~~~~~~~
answer.code:71:37: error: ‘query’ was not declared in this scope
   71 |                 if (poz2-1>=poz1+1) query[poz2-1].push_back({poz1+1,i});
      |                                     ^~~~~
answer.code:74:28: error: ‘query’ was not declared in this scope
   74 |             if (poz1-1>=1) query[poz1-1].push_back({1,i});
      |                            ^~~~~
answer.code:76:28: error: ‘query’ was not declared in this scope
   76 |             if (n>=poz2+1) query[n].push_back({poz2+1,i});
      |                            ^~~~~
answer.code:79:21: error: ‘sett’ was not declared in this scope
   79 |         for (auto p:sett)
      |                     ^~~~
answer.code:83:9: error: ‘query’ was not declared in this scope
   83 |         query[n].push_back({1,mex_niza});
      |         ^~~~~