#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define tup tuple<int, int, char, int>
const int nx = 105;
int n, m, dist[nx][nx];
int di[] = {0, 0, -1, 1};
int dj[] = {-1, 1, 0, 0};
pii src, ed;
char sea[nx][nx];
char d[] = {'W', 'E', 'N', 'S'};
vector<pair<int, char>> res;
map<char, int> dir;
queue<tup> q;
int main()
{
cin.tie(NULL)->sync_with_stdio(false);
cin >> n >> m;
for(int i=1;i<=n;i++) {
for(int j=1;j<=m;j++) {
cin >> sea[i][j];
if(sea[i][j] == 'o') src = {i, j};
if(sea[i][j] == 'x') ed = {i, j};
dist[i][j] = INT_MAX;
}
}
dir['<'] = 0;
dir['>'] = 1;
dir['^'] = 2;
dir['v'] = 3;
for(int i=0;i<4;i++) {
auto [x, y] = src;
q.push({x + di[i], y + dj[i], d[i], 1});
}
while(!q.empty())
{
auto [i, j, ans, cur] = q.front();
q.pop();
if(ed == make_pair(i, j)) {
res.push_back({cur, ans});
continue;
}
if(sea[i][j] == '.' || dist[i][j] < cur) continue;
if(dist[i][j] > cur) dist[i][j] = cur;
int idx = dir[sea[i][j]];
q.push({i + di[idx], j + dj[idx], ans, cur + 1});
}
if(res.empty()) cout << ":(" ;
else
{
int mn = INT_MAX;
char ans;
for(auto [dist, c] : res)
{
if(dist < mn) {
mn = dist;
ans = c;
}
else if(dist == mn && c < ans) {
ans = c;
}
}
cout << ":)\n" << ans;
}
return 0;
}
