#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define db double
using namespace std;
const int N=55,M=N*N;
const db eps=1e-7;
int n,m,fl[N][N]/*,fu[N][N]*/,eh[N][N],el[N][N],cnt[N][N],tot;
db l,r,mid,ans,dis[N][N],w[N][N][5];
bool vis[N][N];
queue<pair<int,int> > q;
bool spfa()
{
//    printf("mid=%.3lf\n",mid);while(q.size())q.pop();for(int i=0;i<=n;i++)for(int j=0;j<=m;j++){q.push(make_pair(i,j));vis[i][j]=1; dis[i][j]=0; cnt[i][j]=0;if(i){w[i][j][0]=fl[i][j]-mid*el[i][j];
//                if(mid<3&&mid>2&&el[i][j]==1)
//                printf("w[%d][%d][0]=%.3lf\n",i,j,w[i][j][0]);
            }if(j){w[i][j][1]=/*-fu[i][j]*/-mid*eh[i][j];
//                if(mid<3&&mid>2&&eh[i][j]==1)
//                printf("w[%d][%d][1]=%.3lf\n",i,j,w[i][j][1]);
            }if(i<n){w[i][j][3]=-fl[i+1][j]-mid*el[i+1][j];
//                if(mid<3&&mid>2&&el[i+1][j]==1)
//                printf("w[%d][%d][3]=%.3lf\n",i,j,w[i][j][3]);
            }if(j<m){w[i][j][2]=/*fu[i][j+1]*/-mid*eh[i][j+1];
//                if(mid<3&&mid>2&&eh[i][j+1]==1)
//                printf("w[%d][%d][2]=%.3lf\n",i,j,w[i][j][2]);
            }}while(q.size()){int x=q.front().first,y=q.front().second;q.pop();vis[x][y]=0;
//        if(mid>2&&mid<3)printf("x=%d y=%d cnt=%d dis=%.3lf\n",x,y,cnt[x][y],dis[x][y]);
//        if(mid>2&&mid<3)printf("fa[%d][%d]=(%d,%d)\n",x,y,fa[x][y][0],fa[x][y][1]);if(x&&dis[x-1][y]<dis[x][y]+w[x][y][0]){dis[x-1][y]=dis[x][y]+w[x][y][0];
//            printf("  w[%d][%d][0]=%.3lf\n",x,y,w[x][y][0]);
//            fa[x-1][y][0]=x; fa[x-1][y][1]=y;cnt[x-1][y]=cnt[x][y]+1;if(cnt[x-1][y]==tot){
//                if(mid>2&&mid<3)
//                    printf("x-1=%d y=%d dis=%.3lf\n",x-1,y,dis[x-1][y]);return 1;}if(!vis[x-1][y])vis[x-1][y]=1,q.push(make_pair(x-1,y));}if(y&&dis[x][y-1]<dis[x][y]+w[x][y][1]){dis[x][y-1]=dis[x][y]+w[x][y][1];
//            printf("  w[%d][%d][1]=%.3lf\n",x,y,w[x][y][1]);
//            fa[x][y-1][0]=x; fa[x][y-1][1]=y;cnt[x][y-1]=cnt[x][y]+1;if(cnt[x][y-1]==tot){
//                if(mid>2&&mid<3)
//                    printf("x=%d y-1=%d dis=%.3lf\n",x,y-1,dis[x][y-1]);return 1;}if(!vis[x][y-1])vis[x][y-1]=1,q.push(make_pair(x,y-1));}if(x<n&&dis[x+1][y]<dis[x][y]+w[x][y][3]){dis[x+1][y]=dis[x][y]+w[x][y][3];
//            printf("  w[%d][%d][3]=%.3lf\n",x,y,w[x][y][3]);
//            fa[x+1][y][0]=x; fa[x+1][y][1]=y;cnt[x+1][y]=cnt[x][y]+1;if(cnt[x+1][y]==tot){
//                if(mid>2&&mid<3)
//                    printf("x+1=%d y=%d dis=%.3lf\n",x+1,y,dis[x+1][y]);return 1;}if(!vis[x+1][y])vis[x+1][y]=1,q.push(make_pair(x+1,y));}if(y<m&&dis[x][y+1]<dis[x][y]+w[x][y][2]){dis[x][y+1]=dis[x][y]+w[x][y][2];
//            printf("  w[%d][%d][2]=%.3lf\n",x,y,w[x][y][4]);
//            fa[x][y+1][0]=x; fa[x][y+1][1]=y;cnt[x][y+1]=cnt[x][y]+1;if(cnt[x][y+1]==tot){
//                if(mid>2&&mid<3)
//                    printf("x=%d y+1=%d dis=%.3lf\n",x,y+1,dis[x][y+1]);return 1;}if(!vis[x][y+1])vis[x][y+1]=1,q.push(make_pair(x,y+1));}}return 0;
}
int main()
{scanf("%d%d",&n,&m); tot=(n+1)*(m+1);//+1!!!for(int i=1;i<=n;i++)for(int j=1,d;j<=m;j++){scanf("%d",&d); r+=d;fl[i][j]=fl[i][j-1]+d;
//            fu[i][j]=fu[i-1][j]+d;
        }for(int i=0;i<=n;i++)for(int j=1;j<=m;j++)scanf("%d",&eh[i][j]);for(int i=1;i<=n;i++)for(int j=0;j<=m;j++)scanf("%d",&el[i][j]);while(r-l>eps){mid=(l+r)/2;if(spfa()) ans=mid,l=mid+eps;else r=mid-eps;}printf("%.3lf\n",ans);return 0;
}