#include <iostream>

#include <queue>

#include <vector>

#include <cstdio>

#include <cstring>

using namespace std;

const int maxn = ;

const int INF = 0x3f3f3f3f;

typedef pair<int,int> P;

struct Edge

{

    int to, cap, cost, rev;

    Edge(int to_, int cap_, int cost_, int rev_):to(to_),cap(cap_),cost(cost_),rev(rev_){}

};

vector<Edge> G[maxn];

int V, n, m, relation[][];

int h[maxn], dist[maxn], prevv[maxn], preve[maxn];

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

{

    G[from].push_back(Edge(to, cap, cost, G[to].size()));

    G[to].push_back(Edge(from, , -cost, G[from].size()-));

}

int min_cost_flow(int s, int t, int f)

{

    int res = ;

    memset(h, , sizeof(h));

    while(f > ) {

        priority_queue<P, vector<P>, greater<P> > pq;

        fill(dist, dist + V, INF);

        dist[s] = ;

        pq.push(P(, s));

        while(!pq.empty()) {

            P p = pq.top(); pq.pop();

            int v = p.second;

            if(dist[v] < p.first)   continue;

            for(int i = ; i < G[v].size(); i++) {

                Edge& e = G[v][i];

                if(e.cap >  && dist[e.to] > dist[v] + e.cost + h[v] - h[e.to]) {

                    dist[e.to] = dist[v] + e.cost + h[v] - h[e.to];

                    prevv[e.to] = v;

                    preve[e.to] = i;

                    pq.push(P(dist[e.to], e.to));

                }

            }

        }

        if(dist[t] == INF)  return -;

        for(int v = ; v < V; v++)  h[v] += dist[v];

        int d = f;

        for(int v = t; v != s; v = prevv[v]) {

            d = min(d, G[prevv[v]][preve[v]].cap);

        }

        f -= d;

        res += d * h[t];

        for(int v = t; v != s; v = prevv[v]) {

            Edge& e = G[prevv[v]][preve[v]];

            e.cap -= d;

            G[v][e.rev].cap += d;

        }

    }

    return res;

}

int main()

{

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

    int T;

    scanf("%d", &T);    getchar();

    while(T--) {

        scanf("%d%d", &n, &m);

        for(int i = ; i < maxn; i++)   G[i].clear();

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

            for(int j = ; j < m; j++) {

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

            }

        }

        int s = n + n * m, t = s + ;

        for(int j = ; j < m; j++) {//工厂

            for(int k = ; k < n; k++) {//将工厂拆成n个点

                add_edge(n + j * n + k, t, , );

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

                    add_edge(i, n + j * n + k, , (k + ) * relation[i][j]);

                }

            }

        }

        for(int i = ; i < n; i++)  add_edge(s, i, , );

        V = t + ;

        printf("%.6f\n", (double)min_cost_flow(s, t, n) / n);

    }

    return ;

}