practica 5.4 consola

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace practica_5._4_console
{
class Program
{
static void Main(string[] args)
{
int C1;
C1 = 0;
do
{
Console.WriteLine("\nINTRODUZCA LA CALIFICACION");
C1 = int.Parse(Console.ReadLine());
Console.WriteLine("\nCalificacion=\t{0}", C1);
}
while (C1>= 0 && C1 <=100);
{
Console.WriteLine("\nCALIFICACION INVALIDA");
}
Console.ReadLine();

}