497: left 26, up 27, right 30, up 33, left 36, up 41, right 44, up 45, right 48, down 51, right 52, down 55, left 62, down 69, right 74, down 75, right 76, down 79, right 80, down 82, right 87, down 93, right 98, up 102, right 104, up 105, right 106, up 107, right 110, up 113, right 115, up 116, right 122, up 127, left 130, up 133, left 136, up 139, left 142, up 143, left 144, up 147, left 150, up 153, left 154, up 155, left 160, down 163, left 165, down 167, left 177, up 178, down 183, right 184, down 187, right 190, down 193, right 195, down 197, right 200, down 203, right 205, down 206, right 208, down 215, right 220, up 223, right 224, up 225, right 226, up 227, right 229, up 230, right 236, up 237, right 238, up 240, right 242, up 247, left 252, up 255, left 258, up 261, left 263, up 265, left 266, up 267, left 268, up 269, left 270, up 271, left 272, up 275, left 276, up 277, left 282, down 285, left 286, down 287, left 293, down 299, left 303, down 309, right 311, down 312, right 314, down 315, right 316, down 317, right 318, down 323, right 328, down 333, right 334, down 335, right 340, up 343, right 344, up 345, right 346, up 347, right 348, up 349, right 352, up 353, right 355, up 357, right 358, up 361, right 366, up 371, left 375, up 377, left 378, up 379, left 380, up 381, left 382, up 385, left 387, up 389, left 392, up 397, left 404, down 407, left 410, down 412, left 415, down 421, left 425, down 426, left 427, up 428, left 429, down 435, right 438, down 439, right 440, down 445, right 448, down 449, right 452, down 457, right 458, down 459, right 464, up 467, right 468, up 469, right 470, up 471, right 474, up 475, right 476, up 477, right 478, up 479, right 480, up 482, right 486, up 487, right 490, up 495, left 497
248: left 26, up 27, right 30, up 33, left 36, up 41, right 44, up 45, right 48, down 51, right 52, down 55, left 62, down 69, right 74, down 75, right 76, down 79, right 80, down 82, right 86, down 91, right 92, down 93, right 98, up 101, right 102, up 103, right 104, up 105, right 106, up 107, right 110, up 114, right 118, up 119, right 122, up 127, left 130, up 131, left 132, up 133, left 134, up 135, left 136, up 139, left 142, up 143, left 144, up 147, left 150, up 153, left 154, up 155, left 160, down 163, left 166, down 169, left 177, down 185, right 189, down 193, right 195, down 197, right 200, down 203, right 206, down 209, right 210, down 213, right 218, up 221, right 222, up 223, right 224, up 225, right 226, up 227, right 230, up 233, right 236, up 239, right 243, down 244, up 247, left 248
Here's my solution https://news.ycombinator.com/item?id=28170735