#include <bits/stdc++.h>
#define F first
#define S second
#define ll long long
#define pb push_back
#define endl '\n'
using namespace std;
const int MOD = 1e9 + 7;
const int N = 510;
int n, m, dis[N][N], used[N][N];
char g[N][N];
map<char, int> mp;
int e(char a, char b) {
if (mp[a] > mp[b]) {
return (4 - mp[a]) + mp[b];
} else return mp[b] - mp[a];
}
void bfs(int x, int y) {
used[x][y] = 1;
dis[x][y] = 0;
queue<pair<int, int>> q;
q.push({x, y});
while(!q.empty()) {
pair<int, int> u = q.front();
x = u.F, y = u.S;
used[x][y] = 1;
if ( x ) { // up
if ( g[x-1][y] == 'S' and dis[x-1][y] > dis[x][y]) {
dis[x-1][y] = dis[x][y];
q.push({x-1,y});
} else if ( g[x-1][y] != 'X' and dis[x-1][y] > dis[x][y] + e(g[x-1][y],'S')) {
dis[x-1][y] = dis[x][y] + e(g[x-1][y], 'S');
q.push({x-1,y});
}
} if ( y ) { // left
if ( g[x][y-1] == 'E' and dis[x][y-1] > dis[x][y]) {
dis[x][y-1] = dis[x][y];
q.push({x,y-1});
} else if ( g[x][y-1] != 'X' and dis[x][y-1] > dis[x][y] + e(g[x][y-1],'E')) {
dis[x][y-1] = dis[x][y] + e(g[x][y-1], 'E');
q.push({x,y-1});
}
} if ( x < n - 1) { //down
if ( g[x+1][y] == 'N' and dis[x+1][y] > dis[x][y]) {
dis[x+1][y] = dis[x][y];
q.push({x+1,y});
} else if ( g[x+1][y] != 'X' and dis[x+1][y] > dis[x][y] + e(g[x+1][y],'N')) {
dis[x+1][y] = dis[x][y] + e(g[x+1][y], 'N');
q.push({x+1,y});
}
} if (y < m - 1) {
if ( g[x][y+1] == 'W' and dis[x][y+1] > dis[x][y]) {
dis[x][y+1] = dis[x][y];
q.push({x,y+1});
} else if ( g[x][y+1] != 'X' and dis[x][y+1] > dis[x][y] + e(g[x][y+1],'W')) {
dis[x][y+1] = dis[x][y] + e(g[x][y+1], 'W');
q.push({x,y+1});
}
}
q.pop();
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m;
mp['N'] = 1;
mp['E'] = 2;
mp['S'] = 3;
mp['W'] = 4;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
dis[i][j] = INT_MAX;
cin >> g[i][j];
}
}
bfs(n-1,m-1);
if ( dis[0][0] == INT_MAX)
cout << "-1\n";
else
cout << dis[0][0] << endl;
}
