#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> R = {{-1, 3, 1, 4, 2, -1}, {2, -1, 5, 0, -1, 3}, {4, 0, -1, -1, 5, 1}, {1, 5, -1, -1, 0, 4}, {3, -1, 0, 5, -1, 2}, {-1, 2, 4, 1, 3, -1}};
int main(){
  int H, W;
  cin >> H >> W;
  int sy, sx;
  cin >> sy >> sx;
  sy--;
  sx--;
  int gy, gx;
  cin >> gy >> gx;
  gy--;
  gx--;
  vector<vector<char>> A(H, vector<char>(W));
  for (int i = 0; i < H; i++){
    for (int j = 0; j < W; j++){
      cin >> A[i][j];
    }
  }
  queue<tuple<int, int, int, int>> Q;
  Q.push(make_tuple(sy, sx, 0, 1));
  vector<vector<vector<vector<int>>>> d(H, vector<vector<vector<int>>>(W, vector<vector<int>>(6, vector<int>(6, -1))));
  d[sy][sx][0][1] = 0;
  int ans = -1;
  while (!Q.empty()){
    int y = get<0>(Q.front());
    int x = get<1>(Q.front());
    int t = get<2>(Q.front());
    int f = get<3>(Q.front());
    Q.pop();
    if (y == gy && x == gx && t == 0){
      ans = d[y][x][t][f];
      break;
    }
    int r = R[t][f];
    if (y < H - 1){
      if (A[y + 1][x] == '.' && d[y + 1][x][5 - f][t] == -1){
        d[y + 1][x][5 - f][t] = d[y][x][t][f] + 1;
        Q.push(make_tuple(y + 1, x, 5 - f, t));
      }
    }
    if (y > 0){
      if (A[y - 1][x] == '.' && d[y - 1][x][f][5 - t] == -1){
        d[y - 1][x][f][5 - t] = d[y][x][t][f] + 1;
        Q.push(make_tuple(y - 1, x, f, 5 - t));
      }
    }
    if (x < W - 1){
      if (A[y][x + 1] == '.' && d[y][x + 1][5 - r][f] == -1){
        d[y][x + 1][5 - r][f] = d[y][x][t][f] + 1;
        Q.push(make_tuple(y, x + 1, 5 - r, f));
      }
    }
    if (x > 0){
      if (A[y][x - 1] == '.' && d[y][x - 1][r][f] == -1){
        d[y][x - 1][r][f] = d[y][x][t][f] + 1;
        Q.push(make_tuple(y, x - 1, r, f));
      }
    }
  }
  cout << ans << endl;
}