#include <bits/stdc++.h>
#define F first
#define S second
using namespace std;
const int inf = 1e9 + 7;
typedef pair <int, int> pii;
int n, m;
int dis[507][507];
char mat[507][507];
int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};
set <pair <int, pii> > s;
map <char, int> sm;
bool isV(int x, int y) {
return (x >= 0 && x < n && y >= 0 && y < m);
}
int main () {
cin >> n >> m;
sm['E'] = 0;
sm['S'] = 1;
sm['W'] = 2;
sm['N'] = 3;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
dis[i][j] = inf;
s.insert({(i+j) ? inf : 0, {i, j}});
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
cin >> mat[i][j];
}
}
dis[0][0] = 0;
while (!s.empty()) {
pair <int, pii> p = *s.begin();
int px = p.S.F, py = p.S.S;
for (int i = 0; i < 4; i++) {
int cost = (4 + i - sm[mat[px][py]]) % 4;
if (mat[px][py] == 'X') cost = inf;
int nx = px + dx[i], ny = py + dy[i];
if (!isV(nx, ny)) continue;
if (dis[nx][ny] > dis[px][py] + cost) {
s.erase({dis[nx][ny], {nx, ny}});
dis[nx][ny] = dis[px][py] + cost;
s.insert({dis[nx][ny], {nx, ny}});
}
}
s.erase(p);
}
if (dis[n-1][m-1] == inf) {
cout << -1; return 0;
}
cout << dis[n-1][m-1];
return 0;
}
