#include<stdio.h>

int main(void){
  int i;
  char S[101];
  int west = 0, east = 0, flag = 0;
  scanf("%s", S);
  for(i = 0; S[i] != '\0'; i++){
    if(S[i] == 'O') flag = 1;
    else if(S[i] == 'X') flag = 2;
    if(flag == 1){
      east++;
      west = 0;
    }
    else if(flag == 2){
      west++;
      east = 0;
    }
    if(west == 3){
      printf("West\n");
      flag = 3;
      break;
    }
    else if(east == 3){
      printf("East\n");
      flag = 3;
      break;
    }
  }
  if(flag != 3) printf("NA\n");
  return 0;
}