#include <bits/stdc++.h>

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

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

map<int,int> pre;

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

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

struct Itv{
	int l,r;
}q[N];

inline bool cmp(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 bool cmp3(Qr x,Qr y){
	return x.id<y.id;
}

int find(int x){
	if (fa[x]!=x) fa[x]=find(fa[x]);
	return fa[x];
}

void Union(int x,int y){
	int rx=find(x),ry=find(y);
	fa[rx]=ry;
	q[ry]=(Itv){q[rx].l,q[ry].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;
		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,cmp);
		int spc=1;p[n+1].a=0;p[0].a=1e9;
		for (int i=n;i>=0;i--){
			if (p[i].a-p[i+1].a>1){
				spc=p[i+1].a+1;
				break;
			}
		}
		//cout<<spc<<endl;
		for (int i=1;i<=n;i++) fa[i]=i,q[i]=(Itv){i,i};
		for (int i=1;i<=n;i++){
			int j=p[i].id; vis[j]=1;
			if (j>1 && vis[j-1]) Union(j-1,j);
			if (j<n && vis[j+1]) Union(j,j+1);
			Itv curq=q[find(j)];
			tmp[i]=(Qr){a[j]-1,curq.l,curq.r,i,0};
			if (a[j]==1) tmp[i].mns=spc;
		}
		sort(tmp+1,tmp+n+1,cmp2);
		pre.clear();
		for (int i=1,j=1;i<=n;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++;
			}
			tmp[i].s=query(tmp[i].r)-query(tmp[i].l-1);
		}
		int mx=0;
		for (int i=1;i<=n;i++){
			mx=max(mx,tmp[i].s);
			ans=max(ans,mx-tmp[i].mns);
		}
		printf("%d\n",ans);
	}
	return 0;
}