#include <stdio.h>
#include <string>
int main(){
    //input
    char S[101];
    scanf("%s",S);
    std::string s(S);

    //search
    int count_O = 0;
    int count_X = 0;
    for (int i = 0;i < s.length();i++){
        if (count_O < 3 && count_X < 3){
            if (s[i] == 'O'){
                count_O++;
                count_X = 0;
            }
            if (s[i] == 'X'){
                count_X++;
                count_O = 0;
            }
        }else{
            break;
        }
    }

    //output
    if (count_O == 3){
        printf("East\n");
    }else if (count_X == 3){
        printf("West\n");
    }else{
        printf("NA\n");
    }
    return 0;
}