if (first[n] == 18) set_window_background();
void palette_set(int n, int r, int g, int b){    static const int first[21] = {	0, 2, 4, 6, 8, 10, 12, 14,	1, 3, 5, 7, 9, 11, 13, 15,	16, 17, 18, 20, 22    };    real_palette_set(first[n], r, g, b);    if (first[n] >= 18)	real_palette_set(first[n] + 1, r, g, b);}