#include <iostream>
#include <vector>
#include <queue>
using namespace std;

vector<vector<int>> bfs(int si, int sj, int ei, int ej, int n, int m, vector<string>& grid) {
    vector<vector<bool>> visited(n, vector<bool>(m, false));
    vector<vector<int>> dist(n, vector<int>(m, -1));
    queue<tuple<int, int, int>> q;
    q.push({si, sj, 0});
    visited[si][sj] = true;

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

    while (!q.empty()) {
        auto [ci, cj, d] = q.front();
        q.pop();

        if (ci == ei && cj == ej) {
            cout << d << endl;
            exit(0);
        }

        if(grid[ci][cj] == '#') {
            dist[ci][cj] = d;
            continue;
        }

        for (int k = 0; k < 4; k++) {
            int ni = ci + di[k];
            int nj = cj + dj[k];

            if (ni >= 0 && ni < n && nj >= 0 && nj < m && !visited[ni][nj]) {
                visited[ni][nj] = true;
                q.push({ni, nj, d + 1});
            }
        }
    }

    return dist;
}

int main() {
    int n, m;
    cin >> n >> m;
    vector<string> grid(n);
    for (int i = 0; i < n; i++) {
        cin >> grid[i];
    }

    int si = -1, sj = -1, ei = -1, ej = -1;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (grid[i][j] == 'S') {
                si = i;
                sj = j;
            } else if (grid[i][j] == 'E') {
                ei = i;
                ej = j;
            }
        }
    }

    vector<vector<int>> dist_S = bfs(si, sj, ei, ej, n, m, grid);

    int longest_path = -1;
    vector<vector<int>> dist_E = bfs(ei, ej, si, sj, n, m, grid);
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(grid[i][j] == '#' and dist_S[i][j] != -1 and dist_E[i][j] != -1) {
                longest_path = max(longest_path, dist_S[i][j] + dist_E[i][j]);
            }
        }
    }
    cout << longest_path << endl;
    return 0;
}