#include <bits/stdc++.h>
using namespace std;
const int mxN = 100;
int n, m, si, sj;
string g[mxN];
int best = -1;
char ans;
void solve(char c, int i, int j) {
int d = 0;
while(1) {
assert(0 <= i && i < n && 0 <= j && j < m);
if (g[i][j] == 'x') {
if (best == -1 || d < best) {
best = d;
ans = c;
}
return;
}
if (g[i][j] == '.' || g[i][j] == 'o') return;
if (g[i][j] == '>') ++j;
else if (g[i][j] == '<') --j;
else if (g[i][j] == '^') --i;
else if (g[i][j] == 'v') ++i;
else assert(0);
++d;
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
for (int i = 0; i < n; ++i) {
cin >> g[i];
for (int j = 0; j < m; ++j) {
if (g[i][j] == 'o') {
si = i, sj = j;
}
}
}
if (sj + 1 < m) solve('E', si, sj + 1);
if (1 <= si) solve('N', si - 1, sj);
if (si + 1 < n) solve('S', si + 1, sj);
if (1 <= sj) solve('W', si, sj - 1);
if (best != -1) {
cout << ":)\n" << ans;
}
else {
cout << ":(";
}
return 0;
}
