#include<bits/stdc++.h>
using namespace std;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
const char cc[] = {'N', 'E', 'S', 'W'};
int n, m;
vector<string> grid;
vector<vector<int>> dist;
priority_queue<tuple<int, int, int>, vector<tuple<int, int, int>>, greater<>> pq;
int val(char c) {
if (c == 'N') return 1;
if (c == 'E') return 2;
if (c == 'S') return 3;
if (c == 'W') return 4;
return 0;
}
int rot(char a, char b) {
return (val(b) - val(a) + 4) % 4;
}
bool inside(int x, int y) {
return x >= 0 && x < n && y >= 0 && y < m;
}
signed main() {
cin >> n >> m;
grid.resize(n);
dist.assign(n, vector<int>(m, 1000000000));
for (int i = 0; i < n; i++) {
cin >> grid[i];
}
pq.push({0,0,0});
while (!pq.empty()) {
auto [d, x, y] = pq.top();
pq.pop();
if (grid[x][y] == 'X') continue;
for (int i = 0; i < 4; i++) {
int nx = x + dx[i], ny = y + dy[i], c = cc[i];
if (inside(nx, ny) && dist[nx][ny] > d + rot(grid[x][y], c)) {
dist[nx][ny] = d + rot(grid[x][y], c);
pq.push({dist[nx][ny], nx, ny});
}
}
}
cout << (dist[n-1][m-1] == 1e9 ? -1 : dist[n-1][m-1]) << '\n';
}
