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

#define N 100

void hantei(const char a[]){
  char s1[]="OOO";
  char s2[]="XXX";
  char *east;
  char *west;

  east = strstr(a,s1);
  west = strstr(a,s2);

  if(east==NULL && west == NULL) puts("NA");
  else if(east==NULL && west!=NULL) puts("West");
  else if(east!=NULL && west == NULL) puts("East");
  else if(east<west) puts("East");
  else puts("West");

}

int main(){
  char S[N+1];
  scanf("%s",S);

  hantei(S);

  return 0;
}