import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int h = (N+1)/2;
        String [] E = {"ne","ushi","tora","u","tatsu","mi","uma","hitsuji","saru","tori","inu","i"};
        String [] A = new String [N];
        int [] B = new int [12];
        int max = 0;
        for(int i=0; i<N; i++){
            //A[i] = sc.next();
            for(int j=0; j<12; j++){
                if( E[j].equals(A[i]) ){
                    B[j]++;
                    max = Math.max(max, B[j]);
                    break;
                }
                if(max>=h){
                    System.out.println("NO");
                    return;
                }
            }
        }
        System.out.println("YES");
    }
}