public static void Main()
double soucet = student1;
soucet = soucet + student2;
soucet = soucet + student3;
soucet = soucet + student4;
soucet = soucet + student5;
double prumernaZnamka = soucet / 5;
Console.Write("Prumerna znamka");
Console.WriteLine(prumernaZnamka);