#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr int Inf = 2000000030;
constexpr ll INF= 2000000000000000001;
constexpr ll MOD = 1000000007;
const double PI = 3.14159265358979323846;
typedef pair<ll,ll> P;
typedef pair<ll,P> PP;

template<typename T> 
vector<T> make_vector(size_t s) {
    return vector<T>(s);
}

template<typename T,typename... Args>
auto make_vector(size_t s,Args... args) {
    return vector(s,make_vector<T>(args...));
}

template<typename T> inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}

template<typename T> inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return 1;
    }
    return 0;
}

ll mod(ll val, ll M) {
    val = val % M;
    if(val < 0) {
        val += M;
    }
    return val;
}

template<typename T>
T RS(T N, T P, T M){
    if(P == 0) return 1;
    if(P < 0) return 0;
    if(P % 2 == 0){
        ll t = RS(N, P/2, M);
        if(M == -1) return t * t;
        return t * t % M;
    }
    if(M == -1) return N * RS(N,P - 1,M);
    return N * RS(N, P-1, M) % M;
}

struct D{
    int y,x,a;
};

int H,W;
int sy,sx,gy,gx;
vector<vector<char>> vec;
vector<P> prev[1010][1010];
int d[1010][1010][6];

vector<int> dy = {-1,0,1,0};
vector<int> dx = {0,-1,0,1};

vector<vector<int>> moved = {
    {1,2,3,4},
    {5,1,0,1},
    {2,5,2,0},
    {0,3,5,3},
    {4,0,4,5},
    {3,4,1,2}
};

int bfs() {
    for(int i = 0;i < H;i++) {
        for(int j = 0;j < W;j++) {
            for(int k = 0;k < 6;k++) {
                d[i][j][k] = Inf;
            }
        }
    }
    d[sy][sx][0] = 0;
    queue<D> que;
    que.push(D{sy,sx,0});
    while(!que.empty()) {
        D p = que.front();
        que.pop();
        for(int i = 0;i < 4;i++) {
            int ny = p.y + dy.at(i);
            int nx = p.x + dx.at(i);
            int a = moved.at(p.a).at(i);
            if(0 <= ny && ny < H && 0 <= nx && nx < W && vec.at(ny).at(nx) == '.') {
                if(chmin(d[ny][nx][a],d[p.y][p.x][p.a] + 1)) {
                    que.push(D{ny,nx,a});
                }
            }
        }
    }
    if(d[gy][gx][0] == Inf) return -1;
    else return d[gy][gx][0];
}

int main() {
    cin >> H >> W;
    cin >> sy >> sx;
    cin >> gy >> gx;
    sy--;
    sx--;
    gy--;
    gx--;
    vec = make_vector<char>(H,W);
    for(int i = 0;i < H;i++) {
        for(int j = 0;j < W;j++) {
            cin >> vec.at(i).at(j);
        }
    }
    cout << bfs() << endl;
}