public class Class1
{
  public decimal Calculate(decimal amount, int type, int years)
  {
    decimal result = 0;
    decimal disc = (years > 5) ? (decimal)5/100 : (decimal)years/100;
    if (type == 1)
    {
      result = amount;
    }
    else if (type == 2)
    {
      result = (amount - (0.1m * amount)) - disc * (amount - (0.1m * amount));
    }
    else if (type == 3)
    {
      result = (0.7m * amount) - disc * (0.7m * amount);
    }
    else if (type == 4)
    {
      result = (amount - (0.5m * amount)) - disc * (amount - (0.5m * amount));
    }
    return result;
  }
}