text: #include <iostream>
  
  int main()
  {
    std::cout << "ciag 1: ";
    int i = 12;
  
    while (i >= -12)
    {
      std::cout << i << " ";
      i -= 4;
    }
  
    std::cout << "\nciag 2: ";
    i = 12;
  
    while (i >= -12)
    {
      if (i != 0)
        std::cout << i << " ";
      i -= 4;
    }
  
    std::cout << "\nciag 3:\n"
              << "Podaj długość ciągu: ";
    int n;
    std::cin >> n;
  
    i = -3;
  
    while (n > 0)
    {
      std::cout << i << " ";
  
      i *= -2;
      n -= 1;
    }
  
    std::cout << "\nciag 4:\n"
              << "Podaj dlugość ciągu: ";
  
    std::cin >> n;
    i = -10;
  
    int sum = 0;
  
    while (n > 0)
    {
      sum += i;
  
      i += 6;
      n -= 1;
    }
  
    std::cout << sum;
  
    return 0;
  }