Inventing the transformer wasn’t challenge enough for Ottó Bláthy — in his spare time he invented puzzles like this:

White to self-mate in 342 moves.

Solution:

1.c4+ Kc1 2.Qd2+ Kb1 3.Qxd1+ Bc1 4.Qb3+ Bb2 5.Qd3+ Kc1 6.Qe3+ Kb1 7.Nd2+ Kc1 8.Nf1+ Kb1 9.Qe4+ Kc1 10.Qf4+ Kb1 11.Qf5+ Kc1 12.Qg5+ Kb1 13.Qg6+ Kc1 14.Bh6+ Rxh6 15.Qxh6+ Kb1 16.Qg6+ Kc1 17.Qg5+ Kb1 18.Qf5+ Kc1 19.Qf4+ Kb1 20.Qe4+ Kc1 21.Qe3+ Kb1 22.Nd2+ Kc1 23.Ne4+ Kb1 24.Qd3+ Kc1 25.Qd2+ Kb1 26.Qd1+ Bc1 27.Qd3+ Kb2 28.Qd4+ Kb1 29.Nc3+ Kb2 30.Nxb5+ Kb1 31.Nc3+ Kb2 32.Ne4+ Kb1 33.Qd3+ Kb2 34.Qc3+ Kb1 35.Qb3+ Bb2 36.Qd3+ Kc1 37.Qe3+ Kb1 38.Nd2+ Kc1 39.Nf1+ Kb1 40.Qd3+ Kc1 41.Qd2+ Kb1 42.Qd1+ Bc1 43.Qd3+ Kb2 44.Qd4+ Kb1 45.Qe4+ Kb2 46.Qe5+ Kb1 47.Qf5+ Kb2 48.Qf6+ Kb1 49.Qg6+ Kb2 50.Qg7+ Kb1 51.Qxb7+ Bb2 52.Qh7+ Kc1 53.Qh6+ Kb1 54.Qg6+ Kc1 55.Qg5+ Kb1 56.Qf5+ Kc1 57.Qf4+ Kb1 58.Qe4+ Kc1 59.Qe3+ Kb1 60.Qd3+ Kc1 61.Qd2+ Kb1 62.Qd1+ Bc1 63.g4 Kb2 64.Qd4+ Kb1 65.Qe4+ Kb2 66.Qe5+ Kb1 67.Qf5+ Kb2 68.Qf6+ Kb1 69.Qg6+ Kb2 70.Qg7+ Kb1 71.Qb7+ Bb2 72.Qh7+ Kc1 73.Qh6+ Kb1 74.Qg6+ Kc1 75.Qg5+ Kb1 76.Qf5+ Kc1 77.Qf4+ Kb1 78.Qe4+ Kc1 79.Qe3+ Kb1 80.Qd3+ Kc1 81.Qd2+ Kb1 82.Qd1+ Bc1 83.Kf8 Kb2 84.Qd4+ Kb1 85.Qe4+ Kb2 86.Qe5+ Kb1 87.Qf5+ Kb2 88.Qf6+ Kb1 89.Qg6+ Kb2 90.Qg7+ Kb1 91.Qb7+ Bb2 92.Qh7+ Kc1 93.Qh6+ Kb1 94.Qg6+ Kc1 95.Qg5+ Kb1 96.Qf5+ Kc1 97.Qf4+ Kb1 98.Qe4+ Kc1 99.Qe3+ Kb1 100.Qd3+ Kc1 101.Qd2+ Kb1 102.Qd1+ Bc1 103.Ke8 Kb2 104.Qd4+ Kb1 105.Qe4+ Kb2 106.Qe5+ Kb1 107.Qf5+ Kb2 108.Qf6+ Kb1 109.Qg6+ Kb2 110.Qg7+ Kb1 111.Qb7+ Bb2 112.Qh7+ Kc1 113.Qh6+ Kb1 114.Qg6+ Kc1 115.Qg5+ Kb1 116.Qf5+ Kc1 117.Qf4+ Kb1 118.Qe4+ Kc1 119.Qe3+ Kb1 120.Qd3+ Kc1 121.Qd2+ Kb1 122.Qd1+ Bc1 123.Kd8 Kb2 124.Qd4+ Kb1 125.Qe4+ Kb2 126.Qe5+ Kb1 127.Qf5+ Kb2 128.Qf6+ Kb1 129.Qg6+ Kb2 130.Qg7+ Kb1 131.Qb7+ Bb2 132.Qh7+ Kc1 133.Qh6+ Kb1 134.Qg6+ Kc1 135.Qg5+ Kb1 136.Qf5+ Kc1 137.Qf4+ Kb1 138.Qe4+ Kc1 139.Qe3+ Kb1 140.Qd3+ Kc1 141.Qd2+ Kb1 142.Qd1+ Bc1 143.Kc8 Kb2 144.Qd4+ Kb1 145.Qe4+ Kb2 146.Qe5+ Kb1 147.Qf5+ Kb2 148.Qf6+ Kb1 149.Qg6+ Kb2 150.Qg7+ Kb1 151.Qb7+ Bb2 152.Qh7+ Kc1 153.Qh6+ Kb1 154.Qg6+ Kc1 155.Qg5+ Kb1 156.Qf5+ Kc1 157.Qf4+ Kb1 158.Qe4+ Kc1 159.Qe3+ Kb1 160.Qd3+ Kc1 161.Qd2+ Kb1 162.Qd1+ Bc1 163.Kb8 Kb2 164.Qd4+ Kb1 165.Qe4+ Kb2 166.Qe5+ Kb1 167.Qf5+ Kb2 168.Qf6+ Kb1 169.Qg6+ Kb2 170.Qg7+ Kb1 171.Qb7+ Bb2 172.Qh7+ Kc1 173.Qh6+ Kb1 174.Qg6+ Kc1 175.Qg5+ Kb1 176.Qf5+ Kc1 177.Qf4+ Kb1 178.Qe4+ Kc1 179.Qe3+ Kb1 180.Qd3+ Kc1 181.Qd2+ Kb1 182.Qd1+ Bc1 183.Ka7 Kb2 184.Qd4+ Kb1 185.Qe4+ Kb2 186.Qe5+ Kb1 187.Qf5+ Kb2 188.Qf6+ Kb1 189.Qg6+ Kb2 190.Qg7+ Kb1 191.Qb7+ Bb2 192.Qh7+ Kc1 193.Qh6+ Kb1 194.Qg6+ Kc1 195.Qg5+ Kb1 196.Qf5+ Kc1 197.Qf4+ Kb1 198.Qe4+ Kc1 199.Qe3+ Kb1 200.Qd3+ Kc1 201.Qd2+ Kb1 202.Qd1+ Bc1 203.Kxa6 Kb2 204.Qd4+ Kb1 205.Qe4+ Kb2 206.Qe5+ Kb1 207.Qf5+ Kb2 208.Qf6+ Kb1 209.Qg6+ Kb2 210.Qg7+ Kb1 211.Qb7+ Bb2 212.Qh7+ Kc1 213.Qh6+ Kb1 214.Qg6+ Kc1 215.Qg5+ Kb1 216.Qf5+ Kc1 217.Qf4+ Kb1 218.Qe4+ Kc1 219.Qe3+ Kb1 220.Qd3+ Kc1 221.Qd2+ Kb1 222.Qd1+ Bc1 223.Ka7 Kb2 224.Qd4+ Kb1 225.Qe4+ Kb2 226.Qe5+ Kb1 227.Qf5+ Kb2 228.Qf6+ Kb1 229.Qg6+ Kb2 230.Qg7+ Kb1 231.Qb7+ Bb2 232.Qh7+ Kc1 233.Qh6+ Kb1 234.Qg6+ Kc1 235.Qg5+ Kb1 236.Qf5+ Kc1 237.Qf4+ Kb1 238.Qe4+ Kc1 239.Qe3+ Kb1 240.Qd3+ Kc1 241.Qd2+ Kb1 242.Qd1+ Bc1 243.Kb8 Kb2 244.Qd4+ Kb1 245.Qe4+ Kb2 246.Qe5+ Kb1 247.Qf5+ Kb2 248.Qf6+ Kb1 249.Qg6+ Kb2 250.Qg7+ Kb1 251.Qb7+ Bb2 252.Qh7+ Kc1 253.Qh6+ Kb1 254.Qg6+ Kc1 255.Qg5+ Kb1 256.Qf5+ Kc1 257.Qf4+ Kb1 258.Qe4+ Kc1 259.Qe3+ Kb1 260.Qd3+ Kc1 261.Qd2+ Kb1 262.Qd1+ Bc1 263.a6 Kb2 264.Qd4+ Kb1 265.Qe4+ Kb2 266.Qe5+ Kb1 267.Qf5+ Kb2 268.Qf6+ Kb1 269.Qg6+ Kb2 270.Qg7+ Kb1 271.Qb7+ Bb2 272.Qh7+ Kc1 273.Qh6+ Kb1 274.Qg6+ Kc1 275.Qg5+ Kb1 276.Qf5+ Kc1 277.Qf4+ Kb1 278.Qe4+ Kc1 279.Qe3+ Kb1 280.Qd3+ Kc1 281.Qd2+ Kb1 282.Qd1+ Bc1 283.a7 Kb2 284.Qd4+ Kb1 285.Qe4+ Kb2 286.Qe5+ Kb1 287.Qf5+ Kb2 288.Qf6+ Kb1 289.Qg6+ Kb2 290.Qg7+ Kb1 291.Qb7+ Bb2 292.Qh7+ Kc1 293.Qh6+ Kb1 294.Qg6+ Kc1 295.Qg5+ Kb1 296.Qf5+ Kc1 297.Qf4+ Kb1 298.Qe4+ Kc1 299.Qe3+ Kb1 300.Qd3+ Kc1 301.Qd2+ Kb1 302.Qd1+ Bc1 303.a8=Q Kb2 304.Qd4+ Kb1 305.Qb7+ Bb2 306.Qh7+ Kc1 307.Qh6+ Kb1 308.Qd1+ Bc1 309.Ka7 Kb2 310.Qf6+ Kb1 311.Qb3+ Bb2 312.Qf5+ Kc1 313.Qf4+ Kb1 314.Qd1+ Bc1 315.Ka6 Kb2 316.Qe5+ Kb1 317.Qb3+ Bb2 318.Qe4+ Kc1 319.Qee3+ Kb1 320.Qd1+ Bc1 321.Ka5 Kb2 322.Qed4+ Kb1 323.Kb4 Qg1 324.Qb3+ Bb2 325.Qdd3+ Kc1 326.Qe3+ Kb1 327.Nd2+ Kc1 328.Ne4+ Kb1 329.Qed3+ Kc1 330.Qd2+ Kb1 331.Qdd1+ Qxd1 332.Qxd1+ Bc1 333.Qd3+ Kb2 334.Qd4+ Kb1 335.Nc3+ Kb2 336.Nb5+ Kb1 337.Qd3+ Kb2 338.Qc3+ Kb1 339.Qb3+ Bb2 340.Qd1+ Bc1 341.Nxa3+ Kb2 342.Qd2+ Bxd2#

This was typical for Bláthy — in one volume of his compositions, the shortest problem required mate in 30 moves.