#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

struct Pos{

    int i;

    int j;

};

bool operator !=(Pos a, Pos b){
    return !(a.i == b.i && a.j == b.j);
}

int main(){
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
    int n, m;
    cin>>n>>m;
    vector<Pos > teleport;
    vector<vector<char> > g(n, vector<char>(m));
    vector<vector<int> > d(n, vector<int>(m, 1e7));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < m; j++){
            cin>>g[i][j];
            if(g[i][j] == 'T'){
                teleport.push_back(Pos{i, j});
            }
        }
    }
    int x1, y1, x2, y2;
    cin>>x1>>y1>>x2>>y2;

    x1--;y1--;x2--;y2--;
    queue<Pos> q;
    q.push(Pos{x1, y1});
    d[x1][y1] = 0;
    while(true){
        Pos v = q.front();
        q.pop();

        for(int di = -1; di <= 1; di++){
            for(int dj = -1; dj <= 1; dj++){
                if(di * di + dj * dj == 1){
                    int ni = v.i + di;
                    int nj = v.j + dj;
                    if(ni >= 0 && ni < n && nj >= 0 && nj < m && d[ni][nj] > d[v.i][v.j]){
                        q.push(Pos{ni, nj});
                        d[ni][nj] = d[v.i][v.j] + 1;
                    }
                }
            }
        }

        if(g[v.i][v.j] == 'T'){
            for(auto i : teleport){
                if(d[i.i][i.j] > d[v.i][v.j]){
                    q.push(i);
                    d[i.i][i.j]  = d[v.i][v.j];
                }
            }
        }
    if(d[x2][y2] != 1e7){
        cout<<d[x2][y2];
        return 0;
    }
    }

    return 0;
}