#include 
#include 
#include 
using namespace std;

int main()
{
    int n, m;
    cin >> n >> m;
    
    char mat[n][m];
    int si, sj;
    int ei, ej;
    
    vector> dzidovi;
    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;
            }
            if(mat[i][j] == '#') {
                dzidovi.push_back(make_pair(i, j));
            }
        }
    }
    
    int res = -1;
    int di[] = {-1, 1, 0, 0};
    int dj[] = {0, 0, -1, 1};
    
    queue q;
    q.push(si);
    q.push(sj);
    q.push(0);
    
    vector> visited(n, vector(m, false));
    vector> dist_from_S(n, vector(m, -1));
    visited[si][sj] = true;
    
    while(!q.empty()) {
        int ci = q.front();
        q.pop();
        int cj = q.front();
        q.pop();
        int dist = q.front();
        q.pop();
        
        if(ci == ei and cj == ej) {
            cout << dist << endl;
            return 0;
        }
        if(mat[ci][cj] == '#') {
            dist_from_S[ci][cj] = dist;
            continue;
        }
        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]) {
                q.push(ti);
                q.push(tj);
                q.push(dist + 1);
                visited[ti][tj] = true;
            }
        }
    }

    
    
    q.push(ei);
    q.push(ej);
    q.push(0);
    vector> visited2(n, vector(m, false));
    vector> dist_from_E(n, vector(m, -1));
    
    while(!q.empty()) {
        int ci = q.front();
        q.pop();
        int cj = q.front();
        q.pop();
        int dist = q.front();
        q.pop();
        
        if(mat[ci][cj] == '#') {
            dist_from_E[ci][cj] = dist;
            continue;
        }
        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 !visited2[ti][tj]) {
                q.push(ti);
                q.push(tj);
                q.push(dist + 1);
                visited2[ti][tj] = true;
            }
        }
    }
 
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(dist_from_S[i][j] != -1 and dist_from_E[i][j] != -1) {
                if(dist_from_S[i][j] + dist_from_E[i][j] > res) {
                    res = dist_from_S[i][j] + dist_from_E[i][j];
                }
            }
        }
    }
    cout << res << endl;
    
  
    return 0;

}