We see that when some variable is 0x1d3, game prints the flag.```
if (iVar6 == 0x1d3) {    system("cat flag.txt");    uVar8 = 0;}```
That magic variable is the board score calculated by piece positions and types.```
ulong calculate_score(long param_1,undefined8 param_2,undefined8 param_3,undefined8 param_4,                     undefined8 param_5,undefined8 param_6)
{  undefined4 uVar1;  int iVar2;  uint local_1c;  int i;  int j;   local_1c = 0;  i = 0;  while (i < 8) {    j = 0;    while (j < 8) {      uVar1 = get_piece_type(param_1 + ((long)j + (long)i * 8) * 0x10);      get_piece_color(param_1 + ((long)j + (long)i * 8) * 0x10);      switch(uVar1) {      case 0:        iVar2 = calc_queen_score(param_1,(ulong)(8 - i),(ulong)(j + 9));        local_1c = local_1c + iVar2;        break;      case 1:        iVar2 = calc_king_score(param_1,(ulong)(8 - i),(ulong)(j + 9));        local_1c = local_1c + iVar2;        break;      case 2:        iVar2 = calc_bishop_score(param_1,(ulong)(8 - i),(ulong)(j + 9));        local_1c = local_1c + iVar2;        break;      case 3:        iVar2 = calc_knight_score(param_1,(ulong)(8 - i),(ulong)(j + 9));        local_1c = local_1c + iVar2;        break;      case 4:        iVar2 = calc_rook_score(param_1,(ulong)(8 - i),(ulong)(j + 9));        local_1c = local_1c + iVar2;        break;      case 5:        iVar2 = calc_pawn_score(param_1,(ulong)(8U - i),(ulong)(j + 9),(ulong)(8U - i),param_5,                                param_6,param_2);        local_1c = local_1c + iVar2;      }      j = j + 1;    }    i = i + 1;  }  return (ulong)local_1c;}```
Re-implementing the scoring algorithm in Python gives following scores for each piece and position:
```def calc_queen_score(x,y):    return x+y
def calc_king_score(x,y):    return x*y
def calc_bishop_score(x,y):    return (x+y)*2
def calc_knight_score(x,y):    return (x%y)
def calc_rook_score(x,y):    return 0x100-x-y
def calc_pawn_score(x,y):    return x-y
 def find_scores(score_func):    for i in range(8):        row = []        for j in range(8):            row.append(str(score_func(8-i, j+9)))        print("\t".join(row))
print("Queen scores:")find_scores(calc_queen_score)
print("King scores:")find_scores(calc_king_score)
print("Bishop scores:")find_scores(calc_bishop_score)
print("Knight scores:")find_scores(calc_knight_score)
print("Rook scores:")find_scores(calc_rook_score)
print("Pawn scores:")find_scores(calc_pawn_score)```
Output:
```Queen scores:17	18	19	20	21	22	23	2416	17	18	19	20	21	22	2315	16	17	18	19	20	21	2214	15	16	17	18	19	20	2113	14	15	16	17	18	19	2012	13	14	15	16	17	18	1911	12	13	14	15	16	17	1810	11	12	13	14	15	16	17King scores:72	80	88	96	104	112	120	12863	70	77	84	91	98	105	11254	60	66	72	78	84	90	9645	50	55	60	65	70	75	8036	40	44	48	52	56	60	6427	30	33	36	39	42	45	4818	20	22	24	26	28	30	329	10	11	12	13	14	15	16Bishop scores:34	36	38	40	42	44	46	4832	34	36	38	40	42	44	4630	32	34	36	38	40	42	4428	30	32	34	36	38	40	4226	28	30	32	34	36	38	4024	26	28	30	32	34	36	3822	24	26	28	30	32	34	3620	22	24	26	28	30	32	34Knight scores:8	8	8	8	8	8	8	87	7	7	7	7	7	7	76	6	6	6	6	6	6	65	5	5	5	5	5	5	54	4	4	4	4	4	4	43	3	3	3	3	3	3	32	2	2	2	2	2	2	21	1	1	1	1	1	1	1Rook scores:239	238	237	236	235	234	233	232240	239	238	237	236	235	234	233241	240	239	238	237	236	235	234242	241	240	239	238	237	236	235243	242	241	240	239	238	237	236244	243	242	241	240	239	238	237245	244	243	242	241	240	239	238246	245	244	243	242	241	240	239Pawn scores:-1	-2	-3	-4	-5	-6	-7	-8-2	-3	-4	-5	-6	-7	-8	-9-3	-4	-5	-6	-7	-8	-9	-10-4	-5	-6	-7	-8	-9	-10	-11-5	-6	-7	-8	-9	-10	-11	-12-6	-7	-8	-9	-10	-11	-12	-13-7	-8	-9	-10	-11	-12	-13	-14-8	-9	-10	-11	-12	-13	-14	-15```
Solution:
We need to make the total score 467 (0x01D3).
Following board satisfies the scoring requirement and prints the flag.```
		A  B  C  D  E  F  G  H 
8    □  □  □  □  ♖  ♛  ♕  □ 7    □  □  □  □  □  □  □  □ 6    □  □  □  □  □  □  □  □ 5    □  □  □  □  □  □  □  □ 4    □  □  □  □  □  □  □  □ 3    □  □  □  □  □  □  □  □ 2    □  □  □  □  □  □  □  □ 1    □  □  □  □  □  □  □  □ ```
`flag{y3s_i_kn0w_p4wns_c4n_m0v3_tw1c3_0n_th31r_f1rst_pl4y}`