#include <bits/stdc++.h>
#define int long long
//definitely not done by chatgpt because my code segfaulted
int r,s;
char a[110][110];
int dx[256], dy[256];
signed main(){
std::cin>>r>>s;
for(int i=1;i<=r;i++){
for(int j=1;j<=s;j++){
std::cin>>a[i][j];
}
}
int sx,sy;
for(int i=1;i<=r;i++){
for(int j=1;j<=s;j++){
if(a[i][j]=='o'){
sx=i; sy=j;
}
}
}
// directions
std::vector<char> dir = {'E','N','S','W'};
dx['N']=-1; dy['N']=0;
dx['S']=1; dy['S']=0;
dx['E']=0; dy['E']=1;
dx['W']=0; dy['W']=-1;
// currents
dx['^']=-1; dy['^']=0;
dx['v']=1; dy['v']=0;
dx['>']=0; dy['>']=1;
dx['<']=0; dy['<']=-1;
int best = 1e18;
char ans = '?';
for(char d:dir){
int x = sx + dx[d];
int y = sy + dy[d];
int step = 1;
while(true){
if(a[x][y]=='.' || a[x][y]=='o') break;
if(a[x][y]=='x'){
if(step < best || (step==best && d<ans)){
best = step;
ans = d;
}
break;
}
char c = a[x][y];
x += dx[c];
y += dy[c];
step++;
}
}
if(best==1e18){
std::cout<<":(\n";
}else{
std::cout<<":)\n";
std::cout<<ans<<"\n";
}
}
