using System;

public class Program

{

    public static void Exercice1()

    {

        Console.WriteLine("Saisir un nombre");

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

        if(a<0)

        { a=-a;

        }

         Console.WriteLine("la valeur absolue est " + a);

    }

    public static void Exercice2()

    {

        Console.WriteLine("liste des carrés < 100");

        int n =1;

        int carre =n*n;

        while(carre<100)

        {

            Console.WriteLine("carre de " + n + " est " + carre);

            n = n+ 1;

            carre =n*n;

        }

    }

    public static void Exercice3()

    {

        Console.WriteLine("Liste des carrés < 100 ");

        for(int i = 1;i<= 9;i++)

        {

            int carre= i*i;

            Console.WriteLine("le carre de "+ i + " est " + carre);

        }

    }

    public static void Exercice4()

    {

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

    int facto = 1;

    while(a >= 1 )

    {

        facto = facto * a;

        a = a-1;

    }

    Console.WriteLine("La factorielle est " + facto);

    }

    public static void Exercice5()

    {

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

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

        int pgcd;

        while( a!=0 && b!=0)

        { if(a>b)

            {a = a-b;

            }

          else 

            { b = b-a;

            }

        }

        if(a==0)

        { pgcd =b;

        }

        else

        { pgcd =a;

        }

        Console.WriteLine("le pgcd est " + pgcd);

    }

    public static void Main()

    {

    }

}