I have this code:

using System;

namespace _121119_zionAVGfilter
{
    class Program
    { 
        static void Main(string[] args)
        {
            int cnt = 0, zion, sum = 0;
            double avg;
            Console.Write("Enter first zion \n");
            zion = int.Parse(Console.ReadLine());
            while (zion != -1)
            {
                while (zion < -1 || zion > 100)
                {
                  Console.Write("zion can be between 0 to 100 only! \nyou can rewrite the zion here, or Press -1 to see the avg\n");
                  zion = int.Parse(Console.ReadLine());
                }

                cnt++;
                sum = sum + zion;
                Console.Write("Enter next zion, if you want to exit tap -1 \n");
                zion = int.Parse(Console.ReadLine());
                if (cnt != 0){}

            }
            if (cnt == 0)
            {
                Console.WriteLine("something doesn't make sence");
            }
            else
            {
                avg = (double)sum / cnt;
                Console.Write("the AVG is {0}", avg);

            }
            Console.ReadLine(); 
        }
    }
}

The problem here is that if in the beginning I enter a negative or bigger than hundred number, I will get this message: "zion can be between 0 to 100 only! \nyou can rewrite the zion here, or Press -1 to see the avg\n". If I then meenter -1, this what that shows up instead of the AVG: "Enter next zion, if you want to exit tap -1 \n." How can I solve this problem so when the number is negative or bigger than hundred and than tap -1 I will see the AVG an not another message?