#include <bits/stdc++.h>

using namespace std;

const int N=5e4;

const int N1=2e3;

#define INF 1e9

#define INF2 1e4

#define eps 1e-7

#define rg register

#define IL inline

int pre[N],aa[N],s,t,n,m;

double dis[N];

bool vis[];

int l,p1[N1][N1],p2[N1][N1],head[];

struct re{

    int a,b,c,flow,from;

    double cost;

}a[N];

IL void arr(int x,int y,int z,int flow,double cost)

{

     a[++l].a=head[x];

     a[l].b=y;

     a[l].c=z;

     a[l].flow=flow;

     a[l].from=x;

     a[l].cost=cost;

     head[x]=l;

}

IL bool bellmanford(double &flow,double &cost)

{

      queue<int>q;

    for (rg int i=;i<=t;i++) dis[i]=INF;

    aa[s]=INF;

    memset(vis,,sizeof(vis));

    q.push(s);

    while (!q.empty())

    {

        rg int x=q.front(); q.pop();

        rg int u=head[x];

        while (u)

        {

          rg  int v=a[u].b;

          if (dis[x]+a[u].cost<dis[v]&&a[u].c>a[u].flow)

          {

               dis[v]=dis[x]+a[u].cost;

               aa[v]=min(aa[x],a[u].c-a[u].flow);

               pre[v]=u;

               if (vis[v])

               {

                     vis[v]=; q.push(v);

                 }

          }

          u=a[u].a;

        }

        vis[x]=;

    }

    if (dis[t]==INF) return();

    rg int x=t; flow+=aa[t]; cost+=aa[t]*dis[t];

    while (pre[x])

    {

        rg int y=pre[x];

        a[y].flow+=aa[t];

        if (y%==) a[y+].flow-=aa[t];

               else a[y-].flow-=aa[t];

        x=a[y].from;

    }

    return ;

}

double flow,cost;

IL void mincost()

{

    while (bellmanford(flow,cost));

}

#define mid (h+t)/2

IL bool check(double x)

{

    l=;

    memset(head,,sizeof(head));

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

      for (rg int j=;j<=n;j++)

      {

          arr(i,j+n,,,-(p1[i][j]-p2[i][j]*x));

          arr(j+n,i,,,(p1[i][j]-p2[i][j]*x));

        }

    s=,t=*n+;

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

    {

        arr(,i,,,); arr(i,,,,);

        arr(i+n,t,,,); arr(t,i+n,,,);

    }

    flow=; cost=;

    mincost();

    if (cost<=) return();

    else return();

}

int main()

{

    std::ios::sync_with_stdio(false);

    cin>>n;

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

      for (rg int j=;j<=n;j++)

        cin>>p1[i][j];

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

      for (rg int j=;j<=n;j++)

        cin>>p2[i][j];

    double h=,t=INF2;

    while (t-h>eps)

    {

        if (check(mid)) h=mid;

        else t=mid;

    }

    printf("%.6f",h);

    return ;

}