ExitButtonHandler and main() are defined outside of your class body. Check your braces. You also have a missing brace on this if() block and no block at all on the (resultb < 8) statement
if (resultb > 8)
{resultb = resultb - 8; . Attention to indentation and blocking standards will go a long way towards preventing these kinds of errors
if (resultb > 8){
resultb = resultb - 8;
outputBTF.setText("You are overstaffed by " + resultb);
}
if (resultb < 8){
resultb = 8 - resultb;
outputBTF.setText("You are understaffed by " + resultb);
}
if (resultb == 8) {
outputBTF.setText("Your staffing is sufficient");
}