public boolean sum28(int[] nums) {
  int count = 0;
  for (int n : nums) {
    if (n == 2) {
      count++;
    }
  }
  return count == 4;
}

public boolean sum28(int[] nums) {
  int count = 0;
  for (int n : nums) {
    if (n == 2) {
      count++;
    }
  }
  return count * 2 == 8;
}

public boolean sum28(int[] nums) {
  int sum = 0;
  for (int n : nums) {
    if (2 == n)
      sum += n;
  }
  return sum == 8;
}