// promotion: David I. Schwartz 1/2000

public class identifiers {
    public static void main(String[] args) {

	// legal characters: A-Z, a-z, 0-9, _, $, 
	// but digit cannot come first!

	// legal identifiers:
	int A, A1, A_1, $A, A$1, ___A___, __1_$;

	// Remember case sensitive!

	// illegal:
	// int 1, 1A, 1_A, 0AA, -A, A#A;
	// try deleting the comment to see what happens

    }

}