never - NEVER!!! - did I say never? - never ever!!
JFrame F = new JFrame();
Variables are always starting lower case. The compiler probably got confused.
SA's demand for reuse:
JButton b1 = new JButton("1");
JButton b2 = new JButton("2");
JButton b3 = new JButton("3");
...
p2.add(b1);
p2.add(b2);
p2.add(b3);
.....
convert to:
ps.add(createButton("1"));
...
private JButton createButton(String strLabel){
}