# include <stdio.h>
# include <string.h>
# define _fin "car.in"
# define _fout "car.out"
# define maxn 501
# define maxd 8
# define maxb 1<<21
# define maxmd 30000
# define inf 25000002
int dy[] = { -1,-1, 0, 1, 1, 1, 0,-1 }, dx[] = { 0,-1,-1,-1, 0, 1, 1, 1 }, ttf[] = { 4, 5, 6, 7, 0, 1, 2, 3 };
int d[maxb], m3[maxmd];
char v[maxn][maxn][maxd], a[maxn][maxn];
int n, m, sol; // lista curenta, lista maxima
int is, js, ie, je;
int l[3][250003]; // lists
int act, crt; // lista / pozitia in ea
inline int ison(int i, int j) { return (i>=1&&i<=n) && (j>=1&&j<=m); }
inline int setflags(int dx, int dy, int dir) { return ( dx << 9 ) + dy + ( dir << 18 ); }
inline void getflags(int a, int &dx, int &dy, int &dir) { dir = a >> 18, dy = a & 511, dx = ( a >> 9 ) & 511; }
int looplist()
{
if ( ++crt > l[ m3[act] ][ 0 ] )
{
l[ m3[act] ][0] = 0;
if ( !l[ m3[act+1] ][0] && !l[ m3[(act+2)] ][0] ) return 0;
while ( !l[ m3[act] ][0] ) ++act; crt = 1;
}
return 1;
}
void readf()
{
freopen(_fin, "r", stdin);
int i, j, k, x;
scanf("%d%d", &n, &m);
scanf("%d%d%d%d", &is, &js, &ie, &je);
for (i=1; i<=n; i++)
for (j=1; j<=m; j++) scanf("%d", &x), a[i][j] = x;
for (i=1; i<=n; i++) for (j=1; j<=m; j++)
if ( !a[i][j] )
for (k=0; k<8; k++)
if ( ison(i+dx[k], j+dy[k]) )
if ( !a[i+dx[k]][j+dy[k]] )
v[ i ][ j ][ k ] = 1;
}
int dir2[maxd][maxd], costs[maxd];
void solve()
{
int i, cx, cy, cdir, cflag, rez, aux, newd;
for (i=0; i<maxb; i++) d[i] = inf;
for (i=0; i<maxmd; i++) m3[i] = i%3;
for (i=0; i<8; i++)
if ( v[ is ][ js ][ i ]==1 )
d[ l[0][ ++l[0][0] ] = setflags(is+dx[i],js+dy[i],ttf[i]) ] = 0;
crt = 1; costs[1]=0, costs[2]=costs[3]=1, costs[4]=costs[5]=2;
for (cdir=0; cdir<8; cdir++)
dir2[cdir][1] = (cdir+4) % 8, dir2[cdir][2] = (cdir+3) % 8, dir2[cdir][3] = (cdir+5) % 8, dir2[cdir][4] = (cdir+2) % 8, dir2[cdir][5] = (cdir+6) % 8;
while ( 1 )
{
cflag = l[ m3[act] ][ crt ];
cdir = cflag >> 18, cy = cflag & 511, cx = ( cflag >> 9 ) & 511;
for (i=1; i<=5; i++)
if ( v[ cx ][ cy ][ dir2[cdir][i] ] )
if ( costs[i] + d[cflag] < d[aux = setflags(cx+dx[dir2[cdir][i]], cy+dy[dir2[cdir][i]], ttf[dir2[cdir][i]] )] )
d[ l[ m3[(newd=(costs[i]+d[cflag]))] ][ ++l[ m3[newd] ][0] ] = aux ] = newd;
rez=looplist();
while ( rez && act > d[ l[ m3[act] ][ crt ] ] ) rez=looplist();
if ( !rez ) break;
}
for (sol = inf, i=0; i<8; i++) if ( d[ setflags(ie,je,i)] < sol ) sol = d[ setflags(ie,je,i) ];
}
void writef()
{
freopen(_fout, "w", stdout);
printf("%d\n", sol==inf?-1:sol);
}
int main()
{
readf();
solve();
writef();
return 0;
}