#include <iostream>
#include <vector>
#include <queue>
using namespace std;
const int maxn = 1005;
int n, m;
char mat[maxn][maxn];

vector<vector<int>> bfs(int si, int sj, bool from_S) {
    vector<vector<int>> dist(n, vector<int>(m, -1));
    vector<vector<bool>> visited(n, vector<bool>(m, false));
    
    visited[si][sj] = true;
    
    queue<int> q;
    q.push(si);
    q.push(sj);
    q.push(0);
    
    int di[] = {-1, 1, 0, 0};
    int dj[] = {0, 0, -1, 1};
    
    while(!q.empty()) {
        int ci = q.front(); q.pop();
        int cj = q.front(); q.pop();
        int shortest_dist = q.front(); q.pop();
        
        if(from_S) {
            if(mat[ci][cj] == 'E') {
                cout << shortest_dist << endl;
                exit(0);
            }
        }
        
        for(int i = 0; i < 4; i++) {
            int ti = ci + di[i];
            int tj = cj + dj[i];
            
            if(ti >= 0 and ti < n and tj >= 0 and tj < m and !visited[ti][tj]) {
                if(mat[ti][tj] == '#') {
                    dist[ti][tj] = shortest_dist + 1;
                }
                else {
                    q.push(ti);
                    q.push(tj);
                    q.push(shortest_dist + 1);
                }
                visited[ti][tj] = true;

            }
        }
        
        
        
        
        
    }
    
    
    
    return dist;
}
int main() {
    ios_base::sync_with_stdio(false);
    
    cin >> n >> m;
    
    int si, sj, ei, ej;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
            
            if(mat[i][j] == 'S') {
                si = i;
                sj = j;
            }
            
            if(mat[i][j] == 'E') {
                ei = i;
                ej = j;
            }
        }
    }
    
    vector<vector<int>> S = bfs(si, sj, true);
    vector<vector<int>> E = bfs(ei, ej, false);
    
    int res = -1;
    
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(mat[i][j] == '#' and S[i][j] != -1 and E[i][j] != -1) {
                res = max(res, S[i][j] + E[i][j]);
            }
        }
    }
    
    cout << res << endl;
    
     return 0;
}