public static float computeDamage(PokemonInstance attacker, PokemonInstance deffender, float attackPower)
    {
        float attackerDamage    = attacker.getAttack();
        float deffenderDeffense = deffender.getDeffense();

        float attackerLevel = attacker.getLevel();

        return(-1 * (((((attackerLevel * 2 / 5) + 2) * attackPower * attackerDamage / deffenderDeffense) / 50) + 2));
    }