#include <bits/stdc++.h>

using namespace std;
const int N=5*1e5+100;

int n,m,ans,T,t,a[N],tr[N],vis[N];

map<int,int> pre;
vector<int> vec[N];

struct node{
	int a,id;
}p[N];

struct Qr{
	int mns,l,r;
}tmp[N];

inline bool cmp1(node x,node y){
	if (x.a==y.a) return x.id<y.id;
	else return x.a<y.a;
}

inline bool cmp2(Qr x,Qr y){
	return x.r<y.r;
}

inline int lowbit(int x){return x&(-x);}

void modify(int x,int k){
    while (x<=n){
        tr[x]+=k;
        x+=lowbit(x);
    }
}

int query(int x){
    int cnt=0;
    while (x){
        cnt+=tr[x];
        x-=lowbit(x);
    }
    return cnt;
}

int main(){
	scanf("%d",&T);
	while (T--){
		scanf("%d%d",&n,&m);
		for (int i=1;i<=n;i++) vis[i]=0,tr[i]=0;
		ans=0;t=0;
		for (int i=1;i<=n;i++){
			scanf("%d",&a[i]);
			p[i].a=a[i];p[i].id=i;
		}
		sort(p+1,p+n+1,cmp1);
		int cur=0;p[0].a=0;p[n+1].a=1e9;
		for (int i=1;i<=n+1;i++)
			if (p[i].a-p[i-1].a>1){
				cur=p[i-1].a+1;
				break;
			}
		for (int i=1;i<cur;i++) vec[i].clear();
		for (int i=1;i<=n;i++)
			if (a[i]<cur) vec[a[i]].push_back(i);
		for (int i=1;i<cur;i++) vec[i].push_back(n+1);
		for (int i=1;i<cur;i++){
			if (vec[i][0]>1) tmp[++t]=(Qr){i,1,vec[i][0]-1};
			for (int j=1;j<vec[i].size();j++)
				if (vec[i][j-1]+1<=vec[i][j]-1) tmp[++t]=(Qr){i,vec[i][j-1]+1,vec[i][j]-1};
		}
		tmp[++t]=(Qr){cur,1,n};
		pre.clear();
		for (int i=1,j=1;i<=t;i++){
			while (j<=tmp[i].r){
				if (pre.find(a[j])!=pre.end()) modify(pre[a[j]],-1);
				modify(j,1);
				pre[a[j]]=j;
				j++;
			}
			ans=max(ans,query(tmp[i].r)-query(tmp[i].l-1)-tmp[i].mns);
		}
		printf("%d\n",ans);
	}
	return 0;
}