#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
 
int main()
{
//    ofstream cout("out.txt");
    int n, m;
    char mat[1000][1000];
    cin >> n >> m;
    queue<int> q;
    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            cin >> mat[i][j];
        }
    }

    bool visited[1000][1000];
    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            visited[i][j] = false;
        }
    }

    int di[] = {1, -1, 0, 0};
    int dj[] = {0, 0, 1, -1};

    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            if (mat[i][j] == 'S'){
                q.push(i);
                q.push(j);
                q.push(0);
                visited[i][j] = true;
            }
        }
    }
    
    while (!q.empty()){
        int ci, cj, dist;
        ci = q.front();
        q.pop();
        cj = q.front();
        q.pop();
        dist = q.front();
        q.pop();

        if (mat[ci][cj] == 'E'){
            cout << dist << endl;
            return 0;
        }

        for (int i = 0; i < 4; i++){
            int ti = ci + di[i], tj = cj + dj[i];
            if (ti >= n or ti < 0 or tj >= m or tj < 0) continue;
            if (visited[ti][tj] == true) continue;
            if (mat[ti][tj] == '#') continue;
            q.push(ti);
            q.push(tj);
            q.push(dist + 1);
            visited[ti][tj] = true;
        }
    }
    int najgolem_pat = -1;
    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            if (mat[i][j] == '#'){
                for (int p = 0; p < n; p++){
                    for (int k = 0; k < m; k++){
                        visited[p][k] = false;
                    }
                }
                q.push(i);
                q.push(j);
                q.push(0);
                visited[i][j] = true;
                int diste = -1, dists = -1;
                while (!q.empty()){
                    int ci, cj, dist;
                    ci = q.front();
                    q.pop();
                    cj = q.front();
                    q.pop();
                    dist = q.front();
                    q.pop();

                    if (mat[ci][cj] == 'E'){
                        diste = dist;
                    }
                    if (mat[ci][cj] == 'S'){
                        dists = dist;
                    }

                    for (int z = 0; z < 4; z++){
                        int ti = ci + di[z], tj = cj + dj[z];
                        if (ti >= n or ti < 0 or tj >= m or tj < 0) continue;
                        if (visited[ti][tj] == true) continue;
                        if (mat[ti][tj] == '#') continue;
                        q.push(ti);
                        q.push(tj);
                        q.push(dist + 1);
                        visited[ti][tj] = true;
                    }
                }
//                cout << diste << " " << dists << endl;
                if(diste == -1 or dists == -1) continue;
                if (diste + dists > najgolem_pat){
                        najgolem_pat = diste + dists;
                }
            }
        }
    }

    cout << najgolem_pat << endl;

    return 0;
}