#include <stdio.h>
#include <stdbool.h>

typedef struct {
  int east;
  int west;
  char scores[101];
} battleInfo;

void which_winner(battleInfo *data);

int main(void)
{
  battleInfo data;

  scanf("%s", data.scores);
  which_winner(&data);

  return 0;
}

void which_winner(battleInfo *data)
{
  bool isFound = false;

  data->west = 0;
  data->east = 0;

  for (int i = 0; data->scores[i] != '\0'; ++i) {
    if (data->scores[i] == 'O') {
      data->east++;
      data->west = 0;
    } else {
      data->west++;
      data->east = 0;
    }

    if (data->east == 3) {
      printf("East\n");
      isFound = true;
      break;
    } else if (data->west == 3) {
      printf("West\n");
      isFound = true;
      break;
    }
  }

  if (isFound == false) {
    printf("NA\n");
  }
}