using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Program_1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnButton1_Click(object sender, EventArgs e)
        {
            int filledin = 0;
            double average;
            double Number1;
            double Number2;
            double Number3;


            if (txtNumber1.Text != "")
            {
                filledin = filledin + 1;
            }
            else if(txtNumber2.Text != ""){
            filledin = filledin + 1;
            }

            else if (txtNumber3.Text != "")
            {
                filledin = filledin + 1;
            }

            Number1 = Convert.ToDouble(txtNumber1.Text);
            Number2 = Convert.ToDouble(txtNumber2.Text);
            Number3 = Convert.ToDouble(txtNumber3.Text);

            average = (Number1 + Number2 + Number3) / filledin;
            lblLabel1.Text = Convert.ToString(average);
            lblLabel1.Visible = true;

        }
    }
    }