//#pragma comment(linker, "/STACK:1024000000,1024000000")

#include<cstdio>

#include<cstring>

#include<cstdlib>

#include<algorithm>

#include<iostream>

#include<sstream>

#include<cmath>

#include<climits>

#include<string>

#include<map>

#include<queue>

#include<vector>

#include<stack>

#include<set>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

typedef pair<int,int> pii;

#define pb(a) push(a)

#define INF 0x1f1f1f1f

#define lson idx<<1,l,mid

#define rson idx<<1|1,mid+1,r

#define PI  3.1415926535898

template<class T> T min(const T& a,const T& b,const T& c) {

    return min(min(a,b),min(a,c));

}

template<class T> T max(const T& a,const T& b,const T& c) {

    return max(max(a,b),max(a,c));

}

void debug() {

#ifdef ONLINE_JUDGE

#else

    freopen("in.txt","r",stdin);

   // freopen("d:\\out1.txt","w",stdout);

#endif

}

int getch() {

    int ch;

    while((ch=getchar())!=EOF) {

        if(ch!=' '&&ch!='\n')return ch;

    }

    return EOF;

}

const int maxn = ;

int N, M;

int cost[maxn][maxn];

void Input()

{

    scanf("%d%d", &N, &M);

    for(int i = ; i <= N; i++)

        for(int j = ; j <= M; j++)

            scanf("%d", &cost[i][j]);

}

struct Edge

{

    int from, to, cost, cap;

};

const int maxv = maxn * maxn + maxn;

vector<int> g[maxv];

vector<Edge> edge;

int n,s,t;

void add(int from, int to, int cost, int cap)

{

    edge.push_back((Edge){from, to, cost, cap});

    g[from].push_back(edge.size() - );

    edge.push_back((Edge){to, from, -cost, });

    g[to].push_back(edge.size() - );

}

void init()

{

    for(int i = ; i <= n; i++)

        g[i].clear();

    edge.clear();

}

void construct()

{

    n = N + N * M + ;

    s = n - ;

    t = n;

    init();

    for(int i = ; i <= N; i++)

        add(s, i, , );

    for(int k = ; k <= N; k++)

    {

        for(int j = ; j <= M; j++)

        {

            int id = N + (k - ) * M + j;

            add(id, t, , );

            for(int i = ; i <= N; i++)

                add(i, id, k * cost[i][j], );

        }

    }

}

int d[maxv];

int inq[maxv];

int road[maxv];

int SPFA()

{

    memset(d, INF, sizeof(d));

    memset(inq, , sizeof(inq));

    queue<int> q;

    q.push(s);

    d[s] = ;

    road[s] = -;

    while(!q.empty())

    {

        int u = q.front(); q.pop();

        inq[u] = false;

        for(int i = ; i < g[u].size(); i++)

        {

            Edge &e = edge[g[u][i]];

            if(e.cap >  && d[u] + e.cost < d[e.to])

            {

                d[e.to] = d[u] + e.cost;

                road[e.to] = g[u][i];

                if(!inq[e.to])

                {

                    inq[e.to] = true;

                    q.push(e.to);

                }

            }

        }

    }

    return d[t] != INF;

}

int MCMF()

{

    int cost = ;

    while(SPFA())

    {

        cost += d[t];

        for(int e = road[t]; e != -; e = road[edge[e].from])

        {

            edge[e].cap -= ;

            edge[e^].cap += ;

        }

    }

    return cost;

}

int main()

{

    debug();

    int t;

    scanf("%d", &t);

    for(int ca = ; ca <= t; ca++)

    {

        Input();

        construct();

        printf("%.6f\n", MCMF() * 1.0 / N);

    }

    return ;

}