public int fixTeen(int n) {
  if (n >= 13 && n <= 19) {
    if (n == 15 || n == 16) {
      return n;
    }
    return 0;
  }
  return n;
}

public int noTeenSum(int a, int b, int c) {
  return fixTeen(a) + fixTeen(b) + fixTeen(c);
}

Create noTeenSum.java