#include <bits/stdc++.h>
#define int long long
using namespace std;
const int INF = 1e18;
map<char, int> mp = {{'N', 0}, {'E', 1}, {'S', 2}, {'W', 3}};
int fark(char a, char b) {
if (a == 'X') return INF;
int tut = mp[b] - mp[a];
if (tut < 0) tut += 4;
return tut;
}
void solve() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, m;
cin >> n >> m;
vector<string> a(n);
for (int i = 0; i < n; ++i) cin >> a[i];
int total = n * m;
vector<vector<pair<int, int>>> edges(total);
auto id = [&](int i, int j) { return i * m + j; };
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
int u = id(i, j);
if (j + 1 < m) {
int v = id(i, j + 1);
int w1 = fark(a[i][j], 'E');
int w2 = fark(a[i][j + 1], 'W');
if (w1 != INF) edges[u].emplace_back(v, w1);
if (w2 != INF) edges[v].emplace_back(u, w2);
}
if (i + 1 < n) {
int v = id(i + 1, j);
int w1 = fark(a[i][j], 'S');
int w2 = fark(a[i + 1][j], 'N');
if (w1 != INF) edges[u].emplace_back(v, w1);
if (w2 != INF) edges[v].emplace_back(u, w2);
}
}
}
vector<int> dist(total, INF);
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
dist[0] = 0;
pq.emplace(0, 0);
while (!pq.empty()) {
auto [d, u] = pq.top(); pq.pop();
if (d > dist[u]) continue;
for (auto [v, w] : edges[u]) {
if (dist[v] > dist[u] + w) {
dist[v] = dist[u] + w;
pq.emplace(dist[v], v);
}
}
}
int result = dist[total - 1];
cout << (result == INF ? -1 : result) << '\n';
}
int32_t main() {
solve();
return 0;
}
