#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define mp make_pair
#define si(x) int(x.size())
const int mod=998244353,MAX=300005,INF=1<<30;

//Wavelet matrix

// https://kopricky.github.io/code/DataStructure_Advanced/wavelet_matrix.html

struct BitRank {
    // block: bit 列を管理, count: block ごとに立っている 1 の数を管理
    vector<unsigned long long> block;
    vector<unsigned int> count;
    BitRank(){}
    void resize(const unsigned int num){
        block.resize(((num + 1) >> 6) + 1, 0);
        count.resize(block.size(), 0);
    }
    // i ビット目を val(0,1) にセット
    void set(const unsigned int i, const unsigned long long val){
        block[i >> 6] |= (val << (i & 63));
    }
    void build(){
        for(unsigned int i = 1; i < block.size(); i++){
            count[i] = count[i - 1] + __builtin_popcountll(block[i - 1]);
        }
    }
    // [0, i) ビットの 1 の数
    unsigned int rank1(const unsigned int i) const {
        return count[i >> 6] +
        __builtin_popcountll(block[i >> 6] & ((1ULL << (i & 63)) - 1ULL));
    }
    // [i, j) ビットの 1 の数
    unsigned int rank1(const unsigned int i, const unsigned int j) const {
        return rank1(j) - rank1(i);
    }
    // [0, i) ビットの 0 の数
    unsigned int rank0(const unsigned int i) const {
        return i - rank1(i);
    }
    // [i, j) ビットの 0 の数
    unsigned int rank0(const unsigned int i, const unsigned int j) const {
        return rank0(j) - rank0(i);
    }
};

class WaveletMatrix
{
private:
    unsigned int height;
    vector<BitRank> B;
    vector<int> pos;
public:
    WaveletMatrix(){}
    WaveletMatrix(vector<int> vec) :
    WaveletMatrix(vec, *max_element(vec.begin(), vec.end()) + 1){}
    // sigma:文字の種類数
    WaveletMatrix(vector<int> vec, const unsigned int sigma){
        init(vec, sigma);
    }
    void init(vector<int>& vec, const unsigned int sigma){
        height = (sigma == 1) ? 1 : (64 - __builtin_clzll(sigma - 1));
        B.resize(height), pos.resize(height);
        for(unsigned int i = 0; i < height; ++i){
            B[i].resize(vec.size());
            for(unsigned int j = 0; j < vec.size(); ++j) {
                B[i].set(j, get(vec[j], height - i - 1));
            }
            B[i].build();
            auto it = stable_partition(vec.begin(), vec.end(), [&](int c){
                return !get(c, height - i - 1);
            });
            pos[i] = it - vec.begin();
        }
    }
    // val の i ビット目の値を返す(0,1)
    int get(const int val, const int i){
        return val >> i & 1;
    }
    // [l, r) の間に現れる値 val の数
    int rank(const int val, const int l, const int r){
        return rank(val, r) - rank(val, l);
    }
    // [0, i) の間に現れる値 val の数
    int rank(int val, int i){
        int p = 0;
        for(unsigned int j = 0; j < height; ++j){
            if(get(val, height - j - 1)){
                p = pos[j] + B[j].rank1(p);
                i = pos[j] + B[j].rank1(i);
            }else{
                p = B[j].rank0(p);
                i = B[j].rank0(i);
            }
        }
        return i - p;
    }
    // [l, r) の k(0,1,2...) 番目に小さい値を返す
    int quantile(int k, int l, int r){
        int res = 0;
        for(unsigned int i = 0; i < height; ++i){
            const int j = B[i].rank0(l, r);
            if(j > k){
                l = B[i].rank0(l);
                r = B[i].rank0(r);
            }else{
                l = pos[i] + B[i].rank1(l);
                r = pos[i] + B[i].rank1(r);
                k -= j;
                res |= (1 << (height - i - 1));
            }
        }
        return res;
    }
    int rangefreq(const int i, const int j, const int a, const int b,
                  const int l, const int r, const int x){
        if(i == j || r <= a || b <= l) return 0;
        const int mid = (l + r) >> 1;
        if(a <= l && r <= b){
            return j - i;
        }else{
            const int left = rangefreq(B[x].rank0(i), B[x].rank0(j), a, b, l, mid, x + 1);
            const int right = rangefreq(pos[x] + B[x].rank1(i), pos[x] + B[x].rank1(j),
                                        a, b, mid, r, x + 1);
            return left + right;
        }
    }
    // [l,r) で値が [a,b) 内に含まれる数を返す
    int rangefreq(const int l, const int r, const int a, const int b){
        return rangefreq(l, r, a, b, 0, 1 << height, 0);
    }
    int rangemin(const int i, const int j, const int a, const int b,
                 const int l, const int r, const int x, const int val){
        if(i == j || r <= a || b <= l) return -1;
        if(r - l == 1) return val;
        const int mid = (l + r) >> 1;
        const int res = rangemin(B[x].rank0(i),B[x].rank0(j),a,b,l,mid,x+1,val);
        if(res < 0) return rangemin(pos[x] + B[x].rank1(i), pos[x] + B[x].rank1(j),
                                    a, b, mid, r, x + 1, val + (1 << (height - x - 1)));
        else return res;
    }
    // [l,r) で値が [a,b) 内に最小の数を返す(数が存在しない場合は -1 を返す)
    int rangemin(int l, int r, int a, int b){
        return rangemin(l, r, a, b, 0, 1 << height, 0, 0);
    }
};

template<typename T> class OrthogonalRangeCount
{
private:
    using ptt = pair<T, T>;
    const int sz;
    vector<T> X, Y;
    WaveletMatrix wm;
    
public:
    OrthogonalRangeCount(vector<ptt> candidate)
    : sz((int)candidate.size()), X(sz), Y(sz){
        sort(candidate.begin(), candidate.end());
        vector<int> vec(sz);
        for(int i = 0; i < sz; ++i){
            X[i] = candidate[i].first, Y[i] = candidate[i].second;
        }
        sort(Y.begin(), Y.end());
        Y.erase(unique(Y.begin(), Y.end()), Y.end());
        for(int i = 0; i < sz; ++i){
            vec[i] = lower_bound(Y.begin(), Y.end(), candidate[i].second) - Y.begin();
        }
        wm.init(vec, Y.size());
    }
    // [lx,rx) × [ly, ry) の長方形領域に含まれる点の数を答える
    int query(const T lx, const T ly, const T rx, const T ry){
        const int lxid = lower_bound(X.begin(), X.end(), lx) - X.begin();
        const int rxid = lower_bound(X.begin(), X.end(), rx) - X.begin();
        const int lyid = lower_bound(Y.begin(), Y.end(), ly) - Y.begin();
        const int ryid = lower_bound(Y.begin(), Y.end(), ry) - Y.begin();
        if(lxid >= rxid || lyid >= ryid) return 0;
        return wm.rangefreq(lxid, rxid, lyid, ryid);
    }
};

// https://kopricky.github.io/code/SegmentTrees/Basic/static_rangemexquery.html

class RangeMexQuery {
private:
    int n, m;
    vector<array<int, 3> > ptr;
    vector<int> arr, st;
    int update(const int prv, const int id, const int val, const int l, const int r){
        const int cur = (int)ptr.size();
        ptr.push_back({0, 0, id});
        if(r - l == 1) return cur;
        const int mid = (l + r) / 2;
        if(val < mid){
            const int res = update(ptr[prv][0], id, val, l, mid);
            ptr[cur][0] = res, ptr[cur][1] = ptr[prv][1];
        }else{
            const int res = update(ptr[prv][1], id, val, mid, r);
            ptr[cur][0] = ptr[prv][0], ptr[cur][1] = res;
        }
        ptr[cur][2] = min(ptr[ptr[cur][0]][2], ptr[ptr[cur][1]][2]);
        return cur;
    }
    void preprocessing(const vector<int>& vec){
        arr[0] = 0;
        for(int i = 0; i < n; ++i) arr[2 * i + 1] = vec[i], arr[2 * i + 2] = vec[i] + 1;
        sort(arr.begin(), arr.end());
        arr.erase(unique(arr.begin(), arr.end()), arr.end());
        m = (int)arr.size(), st[0] = 0, ptr.push_back({0, 0, -1});
        for(int i = 0; i < n; ++i){
            const int val = (int)(lower_bound(arr.begin(), arr.end(), vec[i]) - arr.begin());
            st[i + 1] = update(st[i], i, val, 0, m);
        }
    }
    int query(const int cur, const int cri, const int l, const int r){
        if(cur == 0 || r - l == 1) return arr[l];
        const int mid = (l + r) / 2;
        if(ptr[ptr[cur][0]][2] < cri) return query(ptr[cur][0], cri, l, mid);
        else return query(ptr[cur][1], cri, mid, r);
    }
public:
    RangeMexQuery(const vector<int>& vec) : n((int)vec.size()), arr(2 * n + 1), st(n + 1){
        preprocessing(vec);
    }
    int query(const int l, const int r){
        return query(st[r], l, 0, m);
    }
};

int main(){
    
    std::ifstream in("text.txt");
    std::cin.rdbuf(in.rdbuf());
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    int Q;cin>>Q;
    while(Q--){
        int N,M;cin>>N>>M;
        vector<int> def(N);
        for(int i=0;i<N;i++){
            cin>>def[i];def[i]--;
        }
        RangeMexQuery RMQ(def);
        
        vector<pair<int,int>> use;
        for(int i=0;i<N;i++){
            use.push_back(mp(def[i],i));
        }
        sort(all(use));
        
        vector<int> WMdef(N,1<<27);
        
        for(int i=0;i+1<N;i++){
            if(use[i].fi==use[i+1].fi) WMdef[use[i].se]=use[i+1].se;
        }
        
        WaveletMatrix WM(WMdef);
        
        int ans=-INF;
        
        int i=0;
        while(i<N){
            int j=i;
            while(j<N&&use[i].fi==use[j].fi) j++;
            for(int k=i;k<j;k++){
                if(k==i){
                    int L=0,R=use[k].se;
                    chmax(ans,R-L-WM.rangefreq(L,R,0,R)-RMQ.query(L,R)-1);
                }
                if(k==j-1){
                    int L=use[k].se+1,R=N;
                    chmax(ans,R-L-WM.rangefreq(L,R,0,R)-RMQ.query(L,R)-1);
                }
                if(k+1<j){
                    int L=use[k].se+1,R=use[k+1].se;
                    chmax(ans,R-L-WM.rangefreq(L,R,0,R)-RMQ.query(L,R)-1);
                }
            }
            i=j;
        }
        
        {
            int L=0,R=N;
            chmax(ans,R-L-WM.rangefreq(L,R,0,R)-RMQ.query(L,R)-1);
        }
        
        cout<<ans<<"\n";
    }
}