#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 200005
#define inf 0x3f3f3f3f

int n,k,a[maxn][5],Mx,mn,V=60000;
vector<vi>v[maxn];
bool make(int s1,int r,int s2){
	For(i,1,n){
		v[i].clear();
		For(j,0,k-1)
			if(a[i][j]>=s1 && a[i][(j+r)%k]<=s2){
				vi o;
				For(x,0,k-1)if(x!=0&&x!=r)o.pb(a[i][(j+x)%k]);
				v[i].pb(o);
			}
		if(!v[i].size())return 0;
	}return 1;
}
int t[maxn],len,id[maxn];
int cnt[maxn];
vi buc[maxn];

int mx[maxn<<2],tag[maxn<<2];
void add(int p,int l,int r,int nl,int nr,int v){
	if(l>=nl&&r<=nr)return tag[p]+=v,mx[p]+=v,void();
	int mid=l+r>>1;
	if(nl<=mid)add(p<<1,l,mid,nl,nr,v);
	if(nr>mid)add(p<<1|1,mid+1,r,nl,nr,v);
	mx[p]=max(mx[p<<1],mx[p<<1|1])+tag[p];
}
void des(vi&o){sort(o.begin(),o.end()),o.erase(unique(o.begin(),o.end()),o.end());}

bool f[9][9];
bool chk(int mid){
	For(R,1,k-1){
		if(!make(Mx-mid,R,mn+mid))continue;
		if(k==2)return 1;
		if(k==3){
			For(i,1,len)buc[i].clear();
			For(i,1,n){
				cnt[i]=0;
				for(auto it:v[i])buc[id[it[0]]].pb(i);
			}
			int j=1,sum=0;
			For(i,1,len){
				for(;t[i]-t[j]>mid;++j) for(int x:buc[j]) --cnt[x],sum-=(!cnt[x]);
				for(int x:buc[i]) sum+=(!cnt[x]),++cnt[x];
				if(sum==n)return 1;
			}
			continue;
		}
		vector<pair<int,pii>>o;
		For(_,1,n){
			vi vx,vy;
			for(auto it:v[_]) vx.pb(it[0]),vx.pb(it[0]+mid+1),vy.pb(it[1]),vy.pb(it[1]+mid+1);
			des(vx),des(vy);
			int sx=vx.size()-1,sy=vy.size()-1;
			memset(f,0,sizeof f);
			for(auto it:v[_])
				For(i,0,sx-1) if(it[0]<=vx[i] && it[0]+mid+1>=vx[i+1])
					For(j,0,sy-1) if(it[1]<=vy[j] && it[1]+mid+1>=vy[j+1]) f[i+1][j+1]=1;
			int cnt=0;
			For(i,1,sx+1){
				for(int l=1,r;l<=sy;l=r+1){
					r=l;
					while(r<n && f[i][r+1]==f[i][r] && f[i-1][r+1]==f[i-1][r])++r;
					if(f[i][l]==f[i-1][l])continue;
					++cnt;
					if(f[i][l]) o.pb(mkp(vx[i-1],mkp(vy[l-1],vy[r]-1)));
					else o.pb(mkp(vx[i-1],mkp(-vy[l-1],vy[r]-1)));
				}
			}
		}
		sort(o.begin(),o.end());
		bool ok=0;
		for(auto qwq:o){
			auto t=qwq.se;
			if(t.fi<0)add(1,0,V,-t.fi,t.se,-1);
			else add(1,0,V,t.fi,t.se,1);
			if(mx[1]==n)ok=1;
		}
		if(ok)return 1;
	}
	return 0;
}
void work()
{
	cin>>n;; Mx=-V,mn=V; len=0;
	For(i,0,k-1)For(j,1,n)cin>>a[j][i],Mx=max(Mx,a[j][i]),mn=min(mn,a[j][i]),t[++len]=a[j][i];
	sort(t+1,t+len+1),len=unique(t+1,t+len+1)-t-1;
	For(i,1,len)id[t[i]]=i;
	int res=Mx-mn,l=0,r=res-1;
	while(l<=r){
		int mid=l+r>>1;
		if(chk(mid))res=mid,r=mid-1;
		else l=mid+1;
	}
	cout<<res<<"\n";
}

signed main()
{
	int T;cin>>T>>k;
	while(T--)work();
	return 0;
}