#include<stdio.h>
#include<string.h>
int main(){
    int i=0,west,east,len,flag=0;
    char S[101];
    
    scanf("%s",S);
    len=strlen(S);
    
    for(i=0;i<len;i++){
        if(S[i]=='O'){
            east=strncmp(&S[i],"OOO",3);
            if(east==0){
                printf("East");
                flag=1;
                break;
            }
            
        }
            
        else{
            west=strncmp(&S[i],"XXX",3);
            if(west==0){
                printf("West");
                flag=1;
                break;
            }
        }
    }
    if(flag==0) printf("NA");
    
}