#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define F first
#define S second
#define coy cout<<"YES\n"
#define con cout<<"NO\n"
#define co1 cout<<"-1\n"
#define sc(x) scanf("%lld",&x)
#define all(x) x.begin(),x.end()
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
const int SI=3e5+7;
ll INF=8e18+7;
int dx[] = {1 , -1 , 0 , 0};
int dy[] = {0 , 0 , 1 , -1};
int MOD=1e9+7;
ll n,m ,vis[555][555],ans[555][555];
map <char,ll> mp[4];
char c[555][555];
priority_queue< pair<ll,pair < ll,ll> > > pq;
int main()
{
fast
mp[0]['N']=0,mp[1]['N']=1, mp[2]['N']=2,mp[3]['N']=3;
mp[0]['E']=3,mp[1]['E']=0, mp[2]['E']=1,mp[3]['E']=2;
mp[0]['S']=2,mp[1]['S']=3, mp[2]['S']=0,mp[3]['S']=1;
mp[0]['W']=1,mp[1]['W']=2, mp[2]['W']=3,mp[3]['W']=0;
cin>>m>>n;
for (int i=0;i<m;i++)
for (int u=0;u<n;u++)
cin>>c[i][u];
for (int i=0;i<=m;i++)
for (int u=0;u<=n;u++)
ans[i][u]=-INF;
ans[0][0]=0;
pq.push({0,{0,0}});
while (pq.size())
{
ll d=pq.top().F,x=pq.top().S.F,y=pq.top().S.S;
pq.pop();
if (vis[x][y]||c[x][y]=='X')
continue;
vis[x][y]=1;
if (x>0&&ans[x-1][y]<d-mp[0][c[x][y]])
ans[x-1][y]=d-mp[0][c[x][y]],pq.push({ans[x-1][y],{x-1,y}});
if (y>0&&ans[x][y-1]<d-mp[3][c[x][y]])
ans[x][y-1]=d-mp[3][c[x][y]],pq.push({ans[x][y-1],{x,y-1}});
if (x<m-1&&ans[x+1][y]<d-mp[2][c[x][y]])
ans[x+1][y]=d-mp[2][c[x][y]],pq.push({ans[x+1][y],{x+1,y}});
if (y<n-1&&ans[x][y+1]<d-mp[1][c[x][y]])
ans[x][y+1]=d-mp[1][c[x][y]],pq.push({ans[x][y+1],{x,y+1}});
}
if (ans[m-1][n-1]==-INF)
co1;
else cout <<-ans[m-1][n-1];
// use scanf not cin
return 0;
}
