#include "cstdio"

#include "iostream"

#include "cstring"

#include "vector"

#include "queue"

using namespace std;

#define inf 0x3f3f3f3f

int area[][],dp[<<][],vis[][],dis[][],dir[][]={-,,,,,-,,},n,m,g;

struct status

{

    int x,y,dep;

    status(int x,int y,int dep):x(x),y(y),dep(dep) {}

};

int bfs(status s,status e)

{

    memset(vis,,sizeof(vis));

    vis[s.x][s.y]=true;

    queue<status> Q;

    Q.push(status(s.x,s.y,));

    while(!Q.empty())

    {

        status t=Q.front();Q.pop();

        for(int s=;s<;s++)

        {

            int X=t.x+dir[s][],Y=t.y+dir[s][];

            if(X<||X>n||Y<||Y>m||vis[X][Y]) continue;

            vis[X][Y]=true;

            if(X==e.x&&Y==e.y) return t.dep+;

            Q.push(status(X,Y,t.dep+));

        }

    }

}

int main()

{

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

    while(scanf("%d%d",&n,&m)!=EOF)

    {

        vector<status> stone;

        stone.push_back(status(,,));

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

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

            {

               scanf("%d",&g);

               if(i==&&j==) continue;

               if(g) stone.push_back(status(i,j,));

            }

        for(int i=;i<stone.size();i++)

        {

            for(int j=;j<stone.size();j++)

            {

                if(i==j) dis[i][j]=;

                else {if(!dis[i][j]) dis[i][j]=dis[j][i]=bfs(stone[i],stone[j]);}

            }

        }

        int s=stone.size();

        int cnt=<<s;

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

        {

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

            {

                if(!i&(<<j)) continue;

                if(i==(<<j)) dp[i][j]=dis[][j];

                else

                {

                    dp[i][j]=inf;

                    for(int k=;k<s;k++) if(i&(<<k)&&k!=j) dp[i][j]=min(dp[i][j],dp[i^(<<j)][k]+dis[k][j]);

                }

            }

        }

        int ans=inf;

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

            ans=min(ans,dp[cnt-][i]+dis[i][]);

        printf("%d\n",ans);

        memset(dp,,sizeof(dp));

        memset(dis,,sizeof(dis));

    }

}