text: extern int printf();
  extern int scanf();
  
  int proov(int x) {
    int a;
    a = 0;
    switch (x) {
      case 1:
        a++;
        break;
      case 2:
        a += 2;
        break;
      case 3:
        a += 7;
        break;
      default:
        a--;
    }
    return a;
  }
  
  int main() {
    int i;
    scanf("%d",&i);
    printf("%d\n",proov(i));
  }
  
  