import java.util.function.Consumer;

class P5 {
  public static void main(String[] _args) {
      int sub[] = { 64, 91, 45 };
      P5 obj = new P5();
      int sum = 0;

      for (int i = 0; i < sub.length; i++) {
          obj.grade(sub[i], i + 1);
          sum += sub[i];
      }

      System.out.println("Overall Percentage: " + (float) sum / 3 + "%");
  }

    void grade(int n, int s) {
        System.out.println( "Subject " + s + " grade: " +  (char)( n >= 90 ? 'A' : n < 50 ? 'F' : 'A' + (9 - n / 10)));
    }
}