import java.util.*;
public class Main {
        static Scanner sc = new Scanner(System.in);
        static void myout(Object t){System.out.println(t);}
        static String getStr(){return sc.next();}
        static int getInt(){return sc.nextInt();}
        static Long getLong(){return sc.nextLong();}
        static boolean isNext(){return sc.hasNext();}
        public static void main(String[] args){
          int N = getInt();
          long[] list = new long[N];
          long output = 1;
          for(int i = 0; i < N; i++){
            long p = getLong();
            if(p == 0){
              myout("0");
              return;
            }else{
              p = p % 9;
              if(p == 0){
                p = 9;
              }
            }
            list[i] = p;
          }
          for(int i = 0; i < N; i++){
            output = (output * list[i]) % 9;
            if(output == 0){
              output = 9;
            }
          }
          myout(output);
        }
        //便利メソッド追加枠ここから

        //便利メソッド追加枠ここまで
}