Csharp 如果是，我怎么才能让这个加75，如果不是，我怎么才能减go 100

运行程序时，即使我输入no，它也会添加75.我不知道它为什么要这么做.我对此还是个新手.

Console.WriteLine("Do you smoke? (Y/N)");
            SmokerStatus = Console.ReadLine();
            if (SmokerStatus != "y" || SmokerStatus != "Y" || SmokerStatus != "yes" || SmokerStatus != "Yes")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(75);
            }
            else if (SmokerStatus != "n" || SmokerStatus != "N" || SmokerStatus != "no" || SmokerStatus != "No")
            {
                BaseQuote = BaseQuote - Convert.ToInt32(100);
            }

这是完整的节目，我有同样的问题与条件状态部分.在那两个部分之前，一切都运行得很好.

using System;
using System.Collections;
namespace Insurance
{
    internal class Insurance
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Nationwide Heath Insurance Co.\n");
#pragma warning disable CS0168
#pragma warning disable CS0165
#pragma warning disable CS8600
#pragma warning disable CS8321
#pragma warning disable CS0219
#pragma warning disable CS8601

            int CustomerID = 1;
            int Age;
            decimal BaseQuote = 250;
            String Eir, Gender, FirstName, LastName, UserAge, ConditionStatus, BadConditions, SmokerStatus;
            bool ConditionBool;

            decimal CoverageAmount, BasePremiumRate, AgePremiumFactor,
            SmokingPremiumFactor, HealthConditionFactor, TotalPremium;

            Console.WriteLine("Please enter your first name:");
            FirstName = Console.ReadLine();
            Console.WriteLine("Please enter your last name ");
            LastName = Console.ReadLine();
            Console.WriteLine("Please enter your gender ");
            Gender = Console.ReadLine();
            if (Gender != "male" || Gender != "Male" || Gender != "m" || Gender != "M")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(250);
            }
            else if (Gender != "female" || Gender != "Female" || Gender != "f" || Gender != "F")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(175);
            }
            Console.WriteLine("Please enter your age");
            UserAge = Console.ReadLine();
            Age = Convert.ToInt32(UserAge);
            if (Age < 35)
            {
                BaseQuote = BaseQuote + Convert.ToInt32(50);
            }
            else if (Age > 35 && Age < 55)
            {
                BaseQuote = BaseQuote + Convert.ToInt32(100);
            }
            else if (Age > 55 && Age < 70)
            {
                BaseQuote = BaseQuote + Convert.ToInt32(162.5);
            }
            else if (Age >= 70)
            {
                Console.WriteLine("No Quote Provided");
                Environment.Exit(0);
            }
            Console.WriteLine("Please enter your adress (eircode)");
            Eir = Console.ReadLine();
#pragma warning disable CS8602
            Eir = Eir.ToUpper();
            Console.WriteLine("Do you have an existing health conditions? (Y/N)");
            ConditionStatus = Console.ReadLine();
            if (ConditionStatus != "y" || ConditionStatus != "Y" || ConditionStatus != "yes" || ConditionStatus != "Yes")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(125);
            }
            else if (ConditionStatus != "n" || ConditionStatus != "N" || ConditionStatus != "no" || ConditionStatus != "No")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(0);
            }
            Console.WriteLine("Please list conditions using comas. If none then type 'None' or 'NA'");
            BadConditions = Console.ReadLine();
            Console.WriteLine("Do you smoke? (Y/N)");
            SmokerStatus = Console.ReadLine();
            if (SmokerStatus != "y" || SmokerStatus != "Y" || SmokerStatus != "yes" || SmokerStatus != "Yes")
            {
                BaseQuote = BaseQuote + Convert.ToInt32(75);
            }
            else if (SmokerStatus != "n" || SmokerStatus != "N" || SmokerStatus != "no" || SmokerStatus != "No")
            {
                BaseQuote = BaseQuote - Convert.ToInt32(100);
            }
            /* string BadConditions = "Do you have any existing health conditions? ( y/n )";
            Console.WriteLine(BadConditions);
            ConditionBool = AskCondition(ref BadConditions); */

            Console.WriteLine($"Quote ID: {CustomerID}\n");
            Console.WriteLine($"Name: {FirstName} {LastName}");
            Console.WriteLine($"Age: {Age}");
            Console.WriteLine($"Gender: {Gender}");
            Console.WriteLine($"Address: {Eir}");
            Console.WriteLine($"Health Conditions: {BadConditions}");
            Console.WriteLine($"Quote: {BaseQuote}");
        }

        /*  private static bool AskCondition(ref string BadConditions)
         {
             bool ConditionBool;
             while (true)
             {
                 string ConditionAnswer = Console.ReadLine();
                 if (ConditionAnswer != null && ConditionAnswer == "y")
                 {
                     ConditionBool = true;
                     Console.WriteLine("Please specify your health condition using a coma:");
                     BadConditions = Console.ReadLine();
                     string[] HealthConditions = new string[] { "" };
                     HealthConditions = BadConditions.Split(',');
                     break;
                 }
                 else if (ConditionAnswer != null && ConditionAnswer == "n")
                 {
                     ConditionBool = false;
                     break;
                 }
                 else
                 {
                     Console.WriteLine("Only y or n Allowed");
                 }
             }

             return ConditionBool;
         } */
    }
}