FORM 1:
public partial class Form1 : Form
    {
        public int c;
        public Form1()
        {
            InitializeComponent();
        }
        public void button2_Click(object sender, EventArgs e)
        {
            c = c + 1;
            coinsLabel.Text = c.ToString();
          
        }
        public void button1_Click(object sender, EventArgs e)
        {
          Form2 form2 = new Form2 ();
            form2.Show();
            Hide();
          
        }
FORM 2:
 public partial class Form2 : Form
    {
        
        public Form2()
         
        {
            InitializeComponent();
        }
       public void BackButton_Click(object sender, EventArgs e)
        {
            var form1 = new Form1();
            form1.Show();
            Hide();
           
           
        }
        private void button1_Click(object sender, EventArgs e)
        {
           
            var form1 = new Form1();
            if (form1.c >= 10)
            {
                legnoLabel.Text = "preso";
            }
        }
        public void legnoLabel_TextChanged(object sender, EventArgs e)
        {
            var form1 = new Form1();
            form1.c = form1.c -500;
            
        }
        private void Form2_Load(object sender, EventArgs e)
        {
        
          
        }
       
    }
}