using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Введите a= ");

         int a = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Введите b= ");

                int b = Convert.ToInt32(Console.ReadLine());

​

                double s = 0;

        if ( a ==80){

             s = a * b;

             Console.WriteLine("s= " + s);

               }

​

                else if (a != 80)

​

                {

                    if(b>100)

                    {

                    s = a + b;

                    Console.Write("s= " +s);

                    }

                    else if(b<=100)

                    {

                     s = Math.Sqrt(Math.Pow(a, 2) + Math.Pow(b, 2));

                        Console.WriteLine("s= " + s);

                    }

                }

​

​

    }

}

​

​