#include<bits/stdc++.h>
#define f first
#define int long long
#define s second
using namespace std;
const int N=105,mod=1e9+7,Inf = 1e15 + 1;
int t,dist[N][N],n,m;
char a[N][N];
queue<pair<int,pair<int,int> > > q;
string s;
bool ok(int x,int y){
if(min(x,y)<1 || x>n || y>m) return 0;
return 1;
}
void bfs(){
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++) dist[i][j] = Inf;
while(q.size()){
int d = q.front().f;
int i=q.front().s.f;
int j=q.front().s.s;
q.pop();
dist[i][j] = d;
if(a[i][j] == '.' || a[i][j]=='x') continue;
int dx=0,dy=0;
if(a[i][j]=='>') dx=0,dy=1;
else if(a[i][j]=='<') dx=0,dy=-1;
else if(a[i][j]=='^') dx=-1,dy=0;
else dx=1,dy=0;
if(dist[i+dx][j+dy] > d+1){
dist[i+dx][j+dy] = d+1;
q.push({d+1,{i+dx,j+dy}});
}
}
}
main(){
// t=1;
cin >> n >> m;
int I=0,J=0,I_,J_;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
cin>>a[i][j];
if(a[i][j] == 'o') I=i,J=j;
else if(a[i][j] =='x') I_=i,J_=j;
}
}
// E N S W
int ans = Inf,i=I,j=J;
char ch='a';
if(ok(i,j+1)) q.push({0,{i,j+1}});
bfs();
ans = dist[I_][J_]; ch='E';
if(ok(i-1,j)) q.push({0,{i-1,j}});
bfs();
if(dist[I_][J_]<ans) ans = dist[I_][J_],ch='N';
if(ok(i+1,j)) q.push({0,{i+1,j}});
bfs();
if(dist[I_][J_]<ans) ans = dist[I_][J_],ch='S';
if(ok(i+1,j-1)) q.push({0,{i,j-1}});
bfs();
if(dist[I_][J_]<ans) ans = dist[I_][J_],ch='W';
if(ans==Inf)cout<<":("<<endl; else cout<<":)"<<endl,cout<<ch;
}
