Change visible all buttons create dynamically in loop if I clicked on certain C#

I've got this problem: In the loop I create buttons:

 for (int i = 0; i < poz; i++) { for (int j = 0; j < pion; j++) { Button button = new Button(); button.Size = new Size(30, 30); button.Location = new Point(30 * (i + 1), 30 * (j + 1) + 50); button.Click += new EventHandler(button_Click); Controls.Add(button); } } 

And when I clicked on button, it change visible to false:

 protected void button_Click(object sender, EventArgs e) { Button button = sender as Button; button.Visible = false; } 

But finally, I want to achieve when if I clicked on certain button, all the buttons in this loop change visible to false. My condition is:

 for (int k = 0; k < m; k++) { if (x[k] == i && y[k] == j) { //here buttons change visible to false } } 

...When m is count of elements in x and y arrays, and i is number of buttons horizontally and j is number of buttons in vertical.

I tried using a variable that determines if the button was clicked and many different methods, but none worked. I expect a simple solution.