#include <stdio.h>
#include <string.h>

int main(void)
{
	char s[101], *p, *q, t[] = "OOO", u[] = "XXX", v[] = "East", w[] = "West";
	gets(s);
	if (strstr(s, t) != NULL && strstr(s, u) != NULL) {
		p = strstr(s, t);
		q = strstr(s, u);
		puts(p < q ? v : w);
	}
	else if (strstr(s, t) != NULL) puts(v);
	else if (strstr(s, u) != NULL) puts(w);
	else puts("NA");
	return 0;
}