@EventHandler
    public void craftingEvent(CraftItemEvent event) {
        Material mat = event.getRecipe().getResult().getType();

        if(mat == Material.IRON_HELMET) helmet = true;
        if(mat == Material.IRON_CHESTPLATE) chestplate = true;
        if(mat == Material.IRON_LEGGINGS) leggings = true;
        if(mat == Material.IRON_BOOTS) boots = true;

        if(helmet && chestplate && leggings && boots) achieve();
    }