private void button1_Click(object sender, EventArgs e)
        {

            string[] str = textBox1.Text.Split();
            float[] floatArray = new float[str.Length];
            for (int i = 0; i < str.Length; i++)
            {
                floatArray[i] = float.Parse(str[i]);
            }

            float sum = 0;

            foreach (float i in floatArray)
            {
                sum += i;
            }

            textBox2.Text = sum.ToString();

            using (StreamWriter writer = new StreamWriter("out.txt", true, Encoding.Default))
            {
                writer.WriteLine(textBox1.Text + ";" + textBox2.Text);
            }

        }