class XpLevel {

    public static int levelToExp(int level) {
        return (int) Math.floor(1000 * Math.pow(level, 1.5));
    }

    public static int expToLevel(int exp) {
        double level = Math.pow(exp / 1000.0, 2 / 3.0);
        int a = (int) Math.floor(level);
        int b = (int) Math.ceil(level);
        return levelToExp(b) > exp ? a : b;
    }

    public static void main(String[] args) {
        for (int i = 0; i <= 20; i++) {
            int exp = levelToExp(i);
            System.out.print("Para o level " + i + " precisamos de " + exp + " EXP. ");
            int provaReal = expToLevel(exp);
            int antes = expToLevel(exp - 1);
            int depois = expToLevel(exp + 1);
            System.out.print((exp - 1) + " EXP = Level " + antes + ". ");
            System.out.print(exp + " EXP = Level " + provaReal + ". ");
            System.out.print((exp + 1) + " EXP = Level " + depois + ".");
            System.out.println();
        }
    }
}