#include <bits/stdc++.h>
using namespace std;
int anss[] = {
    0,         2,         1,         32,        30,        80,        109,
    6824,      59808,     147224,    415870,    1757896,   1897056,   4898872,
    7593125,   776830421, 290516100, 746623577, 293783147, 33900006,  735127505,
    565460332, 428982705, 472062098, 161873957, 117354594, 515619293, 578944191,
    312106242, 569389279, 391464593, 261086313, 584837659, 683961846, 468868529,
    211593382, 736955478, 229471758, 157617135, 398169441, 360252438, 629394768,
    264125799, 647490480, 342079395, 391579767, 225200475, 486011304, 513156108,
    628771752, 132906648, 142138221, 20119449,  444199674, 195188679, 387329805,
    44684703,  651912135, 737154512, 612549793, 519860281, 186175544, 212568440,
    240805271, 239509872, 581127897, 6511239,   156126222, 509425833, 672407328,
    366667722, 459185405, 509737025, 554790222, 165216555, 703150560, 74806569,
    398730015, 383350905, 506108358, 51326142,  298053147, 104256117, 391428765,
    374020479, 206607807, 87664059,  275899176, 56407680,  551553401, 448939463,
    582889860, 129676638, 226078251, 135769095, 61292868,  578972226, 190181628,
    390739055, 184587732, 446575689, 732674124, 232198470, 676760679, 352474101,
    611444862, 575661807, 628905585, 320813094, 522840969, 469781928, 156006018,
    554473341, 239654268, 643714911, 433540170, 199307003, 496385218, 291740751,
    67309914,  370826673, 202356819, 279421821, 421203111, 63744786,  520987612,
    550671827, 482164403, 768209115, 462063756, 154906374, 36099042,  341766705,
    678182556, 621882744, 478771358, 231881111, 175889805, 243630450, 168908523,
    671961765, 55761813,  652682670, 773939082, 517628076, 756201264, 124604900,
    750976272, 498253248, 676047609, 137170026, 705610017, 495032139, 561797418,
    703097347, 500815609, 95984586,  739707108, 265613565, 387099846, 777331779,
    594676173, 591219559, 407997044, 208947235, 93337440,  478908360, 685013007,
    487033953, 671903001, 39521181,  738490312, 33785059,  465470131, 310453920,
    54648783,  346831137, 427694175, 474743430, 705296781, 435828036, 429824745,
    663532359, 261388683, 244690731, 533997135, 596108961, 506813013, 371892402,
    590145264, 104733162, 143420103, 654339672, 700348950, 685038942, 578826927,
    286484229, 501639192, 434962491, 299270097, 27702486,  335375775, 111746817,
    565603164, 294926121, 676063665, 735862995, 710035809, 437011960, 668528077,
    138765186, 508213986, 615036450, 353784942, 624827616, 343900011, 241289776,
    52410890,  72018835,  352406796, 415705878, 4802637,   376367145, 65589678,
    333633477, 341834527, 303717460, 282387700, 42951006,  254706039, 423048528,
    526429710, 68131467,  669954708, 12787348,  500636381, 317959019, 479433192,
    657133515, 416259390, 610216692, 340129188, 44594256,  257373347, 138718678,
    530767740, 292922628, 37220268,  605295159, 480722613, 458170419, 30540300,
    487159055, 232966794, 149150650, 412133651, 386543325, 139952108, 289303402,
    102404925, 317067177, 396414708, 80515854,  663739304, 317300809, 228877044,
    493725043, 715317967, 490300965, 315527373, 743539734, 488329191, 553627998,
    533025234, 242583957, 706116537, 614109258, 645447222, 523195911, 492109128,
    722623041, 111085128, 766395126, 654378921, 691964847, 496688157, 399056049,
    654363234, 102052314, 191720088, 473910948, 259736526, 332840025, 388047555,
    665791056, 627111387, 139696515, 441456687, 443032569, 283264821, 771641703,
    452641455, 511306362, 117572859, 127701891, 721298331, 176520078, 357242229,
    611296308, 696994956, 405628839, 429224274, 465336054, 695091546, 689828796,
    574648641, 351220905, 507964023, 675326610, 517248963, 453528621, 220301928,
    494463186, 681789969, 339589656, 44524053,  417125457, 339589404, 747135963,
    341780733, 734158215, 396817281, 21997836,  5728464,   147611205, 456248898,
    714128667, 377654949, 3862068,   128418948, 589390074, 304947090, 11703825,
    228266073, 127304142, 429215724, 361541124, 521572968, 468358191, 341231688,
    65323503,  613778508, 15985323,  291661029, 410970006, 591638112, 349541550,
    89967528,  224922159, 361094166, 584206074, 640051812, 324264456, 652625388,
    693768537, 11740617,  309238398, 211085469, 194905872, 639416484, 110110707,
    296645895, 748118511, 131177718, 511142751, 775975599, 421403409, 475528473,
    434685258, 1768977,   80301375,  708023862, 569195676, 56238084,  632887668,
    88089750,  631539342, 396695565, 38780154,  695798271, 469819224, 439587099,
    69045921,  682966116, 112310856, 64943298,  534475872, 40215357,  389728458,
    286368453, 736006257, 501181650, 54829908,  603489402, 338032656, 512182818,
    627500097, 462674016, 3103092,   157324491, 43978329,  596818971, 259025598,
    9088632,   91991781,  577291428, 211245489, 429471231, 142626330, 172560633,
    510907446, 444609585, 758102058, 375112647, 744786693, 276174402, 19259856,
    233672418, 745389414, 225772848, 23385663,  324290610, 519804558, 120337812,
    402578568, 360676008, 450089262, 551043738, 337388940, 512108856, 28879011,
    690040638, 106017282, 558262341, 99972432,  608226003, 612152037, 42414435,
    776201013, 39580443,  518796945, 494437752, 583194366, 723936555, 415359657,
    309569589, 751104774, 166684527, 249229170, 353120823, 130668327, 753823584,
    580966092, 561963717, 543672234, 393846327, 586278000, 327398400, 278403867,
    156455586, 363920382, 190245195, 290039148, 547014447, 466218648, 146037150,
    585462906, 666008595, 691786683, 374707494, 622498779, 231158277, 685740951,
    115612245, 681825249, 545555745, 551718468, 277206615, 640171035, 757727334,
    195193908, 658656684, 457760646, 225925875, 505761984, 18685233,  506832921,
    112511021, 396846646, 290147622, 113924623, 669986155, 336008070, 63611061,
    238586775, 119956662, 616557739, 772784623, 334527774, 410403148, 51933421};
bool solve() {
  int N, K;
  if (scanf("%d%d", &N, &K) == EOF) return false;
  printf("%d", anss[N + K - 2]);
  return true;
}
int main() {
  solve();
  return 0;
}
