#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define NUM 101
#define MOD 1000000007
using namespace std;
vector <pair<int, int> > gr [NUM][NUM];
bool pos;
int starti, startj, endi, endj, cnt;
void dfs (int i, int j) {
//cout << i << ' ' << j << endl;
cnt ++;
if (i == endi && j == endj) {
return;
}
if (gr[i][j].empty()) {
pos = 0;
return;
}
for (auto nxt : gr[i][j]) {
dfs(nxt.F, nxt.S);
}
return;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
cin >> n >> m;
for (int i = 0; i < n; i ++) {
for (int j = 0; j < m; j ++) {
char c;
cin >> c;
if (c == 'o') {
starti = i;
startj = j;
}
if (c == 'x') {
endi = i;
endj = j;
}
if (c == '^') {
gr[i][j].push_back({i - 1, j});
}
if (c == 'v') {
gr[i][j].push_back({i + 1, j});
}
if (c == '<') {
gr[i][j].push_back({i, j - 1});
}
if (c == '>') {
gr[i][j].push_back({i, j + 1});
}
}
}
int minn = 100000;
string res;
if (startj < m - 1) {
pos = 1;
cnt = 0;
dfs(starti, startj + 1);
if (pos) {
if (minn > cnt) {
res = 'E';
minn = cnt;
}
}
}
//cout << endl;
if (starti > 0) {
pos = 1;
cnt = 0;
dfs(starti - 1, startj);
if (pos) {
if (minn > cnt) {
res = 'N';
minn = cnt;
}
}
}
//cout << endl;
if (starti < n - 1) {
pos = 1;
cnt = 0;
dfs(starti + 1, startj);
if (pos) {
if (minn > cnt) {
res = 'S';
minn = cnt;
}
}
}
//cout << endl;
if (startj > 0) {
pos = 1;
cnt = 0;
dfs(starti, startj - 1);
if (pos) {
if (minn > cnt) {
res = 'W';
minn = cnt;
}
}
}
//cout << endl;
if (minn < 100000) {
cout << ":)" << endl << res;
}
else cout << ":(";
}
