#include<bits/stdc++.h>
using namespace std;
#define int long long
vector<pair<int,int>> adj[200][200];
int x, y, ex, ey;
void dfs(pair<int,int> v, int &ans, bool &found){
// cout << v.first << " " << v.second << endl;
if(v.first == ex && v.second == ey) {
found = true;
return;
}
ans++;
for(auto u : adj[v.first][v.second]){
dfs(u, ans, found);
}
}
signed main(){
int n, m;
cin >> n >> m;
string a[n];
for(int i = 0; i<n; i++) cin >> a[i];
for(int i = 0; i<n; i++){
for(int j = 0; j<m; j++){
if(a[i][j] == '<') adj[i][j].push_back({i, j - 1});
if(a[i][j] == '>') adj[i][j].push_back({i, j + 1});
if(a[i][j] == '^') adj[i][j].push_back({i - 1, j});
if(a[i][j] == 'v') adj[i][j].push_back({i + 1, j});
if(a[i][j] == 'x') ex = i, ey = j;
if(a[i][j] == 'o') x = i, y = j;
}
}
vector<pair<int, char>> vc;
int ans = 0;
if(x > 0) {
bool flag = false;
dfs({x - 1, y}, ans, flag);
if(flag)
vc.push_back({ans, 'N'});
ans = 0;
flag = false;
// cout << endl;
}
if(x < n-1) {
bool flag = false;
dfs({x + 1, y}, ans, flag);
if(flag)
vc.push_back({ans, 'S'});
ans = 0;
flag = false;
// cout << endl;
}
if(y > 0) {
bool flag = false;
dfs({x, y - 1}, ans, flag);
if(flag)
vc.push_back({ans, 'W'});
ans = 0;
flag = false;
// cout << endl;
}
// cout << "gg\n";
if(y < m-1) {
bool flag = false;
dfs({x, y + 1}, ans, flag);
if(flag)
vc.push_back({ans, 'E'});
ans = 0;
flag = false;
// cout << endl;
}
if(vc.size() == 0) cout << ":(\n";
else {
sort(vc.begin(), vc.end());
cout << ":)\n";
// cout << vc.size() << endl;
cout << vc[0].second << endl;
}
}
