#include <iostream>
#include <vector>
#include <set>
#include <cstring>
#include <queue>
using namespace std;
typedef long long ll;
const int maxn = 1005;
int n, m;
char mat[maxn][maxn];
int main()
{
    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>> dist_from_S(n, vector<int>(m, -1));
    vector<vector<bool>> visited(n, vector<bool>(m, false));
    queue<int> q;
    q.push(si);
    q.push(sj);
    q.push(0);
    
    visited[si][sj] = true;
    
    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 dist = q.front(); q.pop();
        
        if(mat[ci][cj] == '#') {
            dist_from_S[ci][cj] = dist;
            continue;
        }
        
        if(mat[ci][cj] == 'E') {
            cout << dist << endl;
            return 0;
        }
        for(int k = 0; k < 4; k++) {
            int ti = ci + di[k];
            int tj = cj + dj[k];
            
            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;
            }
        }
        
    }
    
    visited = vector<vector<bool>>(n, vector<bool>(m, false));
    vector<vector<int>> dist_from_E(n, vector<int>(m, -1));
    q.push(ei);
    q.push(ej);
    q.push(0);
    
    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 k = 0; k < 4; k++) {
            int ti = ci + di[k];
            int tj = cj + dj[k];
            
            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;
            }
        }
    }
    int res = -1;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(dist_from_E[i][j] != -1 and dist_from_S[i][j] != -1) {
                res = max(res, dist_from_E[i][j] + dist_from_S[i][j]);
            }
        }
    }
    cout << res << endl;
    
    
    
    
    return 0;
}