#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
using namespace std;
int a[505][505];
int t[505][505];
int dx[] = {-1,0,1,0};
int dy[] = {0,1,0,-1};
int val[200];
vector < queue < pair <int, int> > > q(4);
string s;
int n,m;
void bfs(int sx, int sy){
    for(int e = 0; e < 4; e++){
        int x = sx + dx[e], y = sy + dy[e];
        if(a[x][y] == -1) continue;
        if(t[x][y] > t[sx][sy] + ((4 + e - a[sx][sy]) & 3)){
            t[x][y] = t[sx][sy] + ((4 + e - a[sx][sy]) & 3);
            q[(4 + e - a[sx][sy]) & 3].push({x,y});
        }
    }
    while(1){
        int temp = inf, c;
        for(int i = 0; i < 4; i++){
            if(q[i].empty()) continue;
            if(t[q[i].front().first][q[i].front().second] < temp){
                temp = t[q[i].front().first][q[i].front().second];
                c = i;
            }
        }
        if(temp == inf) return;
        pair <int, int> f = q[c].front();
        if(f.first == n && f.second == m) return;
        q[c].pop();
        for(int e = 0; e < 4; e++){
            int x = f.first + dx[e], y = f.second + dy[e];
            if(a[x][y] == -1) continue;
            if(t[x][y] > t[f.first][f.second] + ((4 + e - a[f.first][f.second]) & 3)){
                t[x][y] = t[f.first][f.second] + ((4 + e - a[f.first][f.second]) & 3);
                q[(4 + e - a[f.first][f.second]) & 3].push({x,y});
            }
        }
    }
}
int main()
{
    int i,j;
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> m;
    val['N'] = 0;
    val['E'] = 1;
    val['S'] = 2;
    val['W'] = 3;
    val['X'] = -1;
    memset(t, 0x3f, sizeof t);
    for(i = 0; i <= n + 1; i++) a[i][0] = a[i][m + 1] = -1;
    for(i = 0; i <= m + 1; i++) a[0][i] = a[n + 1][i] = -1;
    for(i = 1; i <= n; i++){
        cin.get();
        cin >> s;
        for(j = 0; j < m; j++) a[i][j + 1] = val[s[j]];
    }
    if(a[1][1] == -1){
        cout << -1;
        return 0;
    }
    a[n][m] = 0;
    t[1][1] = 0;
    bfs(1, 1);
//    for(i = 1; i <= n; i++){
//        for(j = 1; j <= m; j++) cout << a[i][j] << " ";
//        cout << "\n";
//    }
//    cout << "\n\n\n";
//    for(i = 1; i <= n; i++){
//        for(j = 1; j <= m; j++) cout << t[i][j] << " ";
//        cout << "\n";
//    }
    if(t[n][m] == inf){
        cout << -1;
        return 0;
    }
    cout << t[n][m];
    return 0;
}