import java.util.regex.Pattern;

public class isPhoneNumber {

    private static final PatternPHONE_REGEX=
            Pattern.compile("^\\\\d{2,3}-\\\\d{3,4}-\\\\d{4}$");

    static boolean isPhoneNumber(String s) {
        returnPHONE_REGEX.matcher(s).matches();
    }

}