private void IncreasePOP()
    {
        App    app    = UnityEngine.Object.FindObjectOfType <App>();
        Nation player = State.getNations()[app.GetHumanIndex()];

        PlayerPayer.payForMorePOP(player);
        if (player.getNumberResource(MyEnum.Resources.wheat) < 1 || player.getAP() < 1 ||
            player.getNumberGood(MyEnum.Goods.clothing) < 1 ||
            (player.getPOPIncreasedThisTurn() > 1 && player.getNumberGood(MyEnum.Goods.chemicals) < 1))
        {
            increasePOP.interactable = false;
        }
        AP.text = player.getAP().ToString();

        freePOP.text = player.getUrbanPOP().ToString();
    }