using System;

namespace Homework_4
{
    class Program
    {
        static void Main(string[] args)
        {
        void ex1() {
            Console.WriteLine("enter a grade");
            int grade = int.Parse(Console.ReadLine());
            if (grade >= 0 && grade <= 100)
            {
                Console.WriteLine("the grade is valid");
            }
            else
            {
                Console.WriteLine("the grade is invalid");
            }
        }

        void ex2() {
            Console.WriteLine("enter a grade");
            int grade = int.Parse(Console.ReadLine());
            
            Console.WriteLine("enter class avg");
            double avg = int.Parse(Console.ReadLine());
            
            double gradeB = grade + (avg/100 * 10);
            if (gradeB > 100)
            {
                gradeB = 100;
            }
            Console.WriteLine("The grade after the bonus is: "+gradeB);
        }

        void ex3() {
            Console.WriteLine("enter a digit");
            int num = int.Parse(Console.ReadLine());
            
            Console.WriteLine("enter another digit");
            int num2 = int.Parse(Console.ReadLine());
            
            if ( (num%2 == 0) && (num2%2 == 1) || (num%2 == 1) && (num2%2 == 0))
            {
                Console.WriteLine("the digits are "+num+" "+num2+" and the sum is: " + (num+num2));
            }
            else
            {
                Console.WriteLine("both numbers are zogi or unzogi");
                
            }
        }

        void ex4() {

            Console.WriteLine("enter a 4 numbered number"); // 5115
            int num = int.Parse(Console.ReadLine());
            int num1 = num%10;
            int num2 = num/10%10;
            int num3 = num/100%10;
            int num4 = num/1000;
            if (num1 == num4 && num2 == num3)
            {
                Console.WriteLine("the num is a palindrom");
            }
            else
            {
                Console.WriteLine("the num is *NOT* a palindrom");
            }

        }

        void ex5() {

            Console.WriteLine("enter a number"); 
            int num  = int.Parse(Console.ReadLine());
            if (num/10 == 0)
            {
                Console.WriteLine("num is singular");
                
            }
            else
            {
                Console.WriteLine("num is plural");
                
            }
            
        }

        void ex6() {
        
            Console.WriteLine("enter num1");
            int num1 = int.Parse(Console.ReadLine());  
            Console.WriteLine("enter num2");
            int num2 = int.Parse(Console.ReadLine());  
            Console.WriteLine("enter num3");
            int num3  = int.Parse(Console.ReadLine()); 
            if ((num1 - num2) == (num2-num3))
            {
                Console.WriteLine("the numbers are making a math street.");
            }
            else
            {
                Console.WriteLine("the numbers are *not* making a math street");
            }
        }

        void ex7() {
            Console.WriteLine("enter a char");
            char ch = char.Parse(Console.ReadLine());
            if ((int)ch >= (int)'a' && (int)ch <= (int)'z')
            {
                Console.WriteLine(ch + " is in the lowercase abc");
            }
            else
            {
                Console.WriteLine(ch + " is not in the lowercase abc");
                
            }

        }
        
        void ex8() {
            Console.WriteLine("enter num1");
            int num1 = int.Parse(Console.ReadLine());
            
            Console.WriteLine("enter num2");
            int num2 = int.Parse(Console.ReadLine());

            Console.WriteLine("enter num3");
            int num3 = int.Parse(Console.ReadLine());
            if ((num1*num1) + (num2*num2) == (num3*num3) || (num1*num1) + (num3*num3) == (num2*num2) || (num2*num2) + (num3*num3) == (num1*num1) ) 
            {
                Console.WriteLine("numbers make a pitogorit trio");
                
            }
            else
            {
                Console.WriteLine("numbers do not make a potogorit trio");
                
            }
        }

        void ex10() {
            Console.WriteLine("enter a 2 numbered num");
            int num = int.Parse(Console.ReadLine());
            int num1,num2;
            num1 = num%10;
            num2 = num/10%10;
            Console.WriteLine(num + " before");
            
            if (num%2 == 0)
            {
                num = num1+1 + (num2+1)*10;
            }
            else
            {
                num = num1-1 + (num2-1)*10;
            }
            Console.WriteLine(num + " after");
            
        }
        
        


        }
    }
}