public static void commonSubstring(List < String > a, List < String > b) {
      // Write your code here
      boolean[] ch = new boolean[26];
      int flag = 0;
      for (int i = 0; i < a.size(); i++) {
          flag = 0;
          ch = new boolean[26];
          for (int j = 0; j < a.get(i).length(); j++) {
              ch[a.get(i).charAt(j) - 'a'] = true;
          }

          for (int j = 0; j < b.get(i).length(); j++) {
              if (ch[b.get(i).charAt(j) - 'a']) {
                  flag = 1;
                  break;
              }
          }

          if (flag == 1)
              System.out.println("YES");
          else
              System.out.println("NO");
      }
  }