#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <cstring>
#include <cctype>
#include <sstream>
#include <set>
#include <map>
#include <queue>
#include <complex>
using namespace std;
#define REP(i,n) for(int i = 0; i < (int)n; i++)
#define FOR(i,a,b) for(int i = a; i < (int)b; i++)
const int INF = 1<<28;

struct P {
	int h, w, d;
	P(int a, int b, int c) {h = a; w = b; d = c;}
	bool operator > (const P& a) const {
		return d > a.d; 
	}
};

int main() {
	int W, H;
	while(cin >> W >> H, W|H) {
		int field[H][W];
		REP(i, H) REP(j, W) {
			char in; cin >> in;
			if(in == '#') field[i][j] = 10;
			else if(in == '.') field[i][j] = 100;
			else if(in == 'X') field[i][j] = 1000;
			else if(in == 'W') field[i][j] = 0;
			else if(in == 'S') field[i][j] = 1;
			else if(in == 'E') field[i][j] = 2;
			else if(in == 'N') field[i][j] = 3;
		}

		queue<P> q;
		priority_queue<P, vector<P>, greater<P> > pq;
		REP(i, H) REP(j, W)
			if(field[i][j] < 4)
				q.push(P(i, j, field[i][j]));

		int cnt = 0;
		while(q.size() | pq.size()) {

			//dicide direction
			while(q.size()) {
				P pp = q.front(); q.pop();
//				cout << pp.h << ' ' << pp.w << ' ' << pp.d << ' ' << cnt << endl;
				REP(i, 4) {
					if((pp.d+i+3)%4 == 0 && 0 < pp.w && field[pp.h][pp.w-1] > 99) {
						pp.d = 0;
						pq.push(pp);
						field[pp.h][pp.w] = 0;
						break;
					}
					else if((pp.d+i+3)%4 == 1 && pp.h<H-1 && field[pp.h+1][pp.w] > 99) {
						pp.d = 1;
						pq.push(pp);
						field[pp.h][pp.w] = 1;
						break;
					}
					else if((pp.d+i+3)%4 == 2 && pp.w < W-1 && field[pp.h][pp.w+1] > 99) {
						pp.d = 2;
						pq.push(pp);
						field[pp.h][pp.w] = 2;
						break;
					}
					else if((pp.d+i+3)%4 == 3 && 0 < pp.h && field[pp.h-1][pp.w] > 99) {
						pp.d = 3;
						pq.push(pp);
						field[pp.h][pp.w] = 3;
						break;
					}
				}
			}

			//dicide move
			while(pq.size()) {
				P pp = pq.top(); pq.pop();
				if(pp.d == 0 && field[pp.h][pp.w-1] > 99) {
					if(field[pp.h][pp.w-1] == 1000)
						field[pp.h][pp.w] = 100;
					else {
						swap(field[pp.h][pp.w], field[pp.h][pp.w-1]);
						q.push(P(pp.h, pp.w-1, pp.d));
					}
				}
				else if(pp.d == 1 && field[pp.h+1][pp.w] > 99) {
					if(field[pp.h+1][pp.w] == 1000)
						field[pp.h][pp.w] = 100;
					else {
						swap(field[pp.h][pp.w], field[pp.h+1][pp.w]);
						q.push(P(pp.h+1, pp.w, pp.d));
					}
				}
				else if(pp.d == 2 && field[pp.h][pp.w+1] > 99) {
					if(field[pp.h][pp.w+1] == 1000)
						field[pp.h][pp.w] = 100;
					else {
						swap(field[pp.h][pp.w], field[pp.h][pp.w+1]);
						q.push(P(pp.h, pp.w+1, pp.d));
					}
				}
				else if(pp.d == 3 && field[pp.h-1][pp.w] > 99) {
					if(field[pp.h-1][pp.w] == 1000)
						field[pp.h][pp.w] = 100;
					else {
						swap(field[pp.h][pp.w], field[pp.h-1][pp.w]);
						q.push(P(pp.h-1, pp.w, pp.d));
					}
				}
				else
					q.push(pp);
			}
			cnt++;
			if(cnt > 180) break;
		}
		if(cnt > 180) cout << "NA" << endl;
		else cout << cnt << endl;
	}
	return 0;
}