#include <fstream>
#include <string.h>

using namespace std;

int main()
{
    ifstream f("date.in");
    ofstream g("date.out");
    int N,K,i,j,dl[]={-1,0,1,0},dc[]={0,1,0,-1},lc,cc,nr_pasi;
    f>>N>>K;
    int etaj[N+1][N+1],pasi[N+1][N+1];
    for(i=1;i<=N;i++)
    {
        for(j=1;j<=N;j++)
        {
            f>>etaj[i][j];
            if(etaj[i][j]!=0)
                pasi[i][j]=0;
            if(etaj[i][j]==0)
                pasi[i][j]=1;
        }

    }
    for(i=0;i<=N+1;i++)
{
    pasi[0][i]=-1;
    pasi[N+1][i]=-1;
    pasi[i][0]=-1;
    pasi[i][N+1]=-1;
}


    struct coada{int l,c;};;
    struct nod{ coada inf;
                nod *urm;};
    nod *p,*u,*q;
    p=u=NULL;
    p=new nod;
    p->inf.l=1;
    p->inf.c=1;
    p->urm=NULL;
    u=p;
    pasi[1][1]=1;
    while(p<=u&&pasi[N][N]==0)
    {
        for(i=0;i<=3;i++)
        {
            lc=p->inf.l+dl[i];
            cc=p->inf.c+dc[i];
            if(pasi[lc][cc]==0)
            {
                q=new nod;
                q->inf.l=lc;
                q->inf.c=cc;
                q->urm=NULL;
                u->urm=q;
                u=q;
                pasi[lc][cc]=pasi[p->inf.l][p->inf.c]+1;

            }

        }
        p=p->urm;
    }
    nr_pasi=pasi[N][N];
    g<<nr_pasi;



    return 0;

}