b21 := (1,3,6,11,19)(2,4,8,14,24)(5,9,16,27,43)(7,12,21,34,54)(10,17,29,46,72) (13,22,36,57,89)(15,25,40,63,99)(18,30,48,75,117)(20,32,51,80,125)(23,37, 59,92,143)(26,41,65,102,157)(28,44,69,108,166)(31,49,77,120,182)(33,52, 82,128,193)(35,55,86,134,202)(38,60,94,146,219)(39,61,96,148,222)(42,66, 104,160,239)(45,70,110,169,253)(47,73,114,174,260)(50,78,122,185,277)(53, 83,130,196,292)(56,87,136,173,95)(58,90,140,210,314)(62,97,150,225,335) (64,100,154,231,345)(67,105,162,242,360)(68,106,164,245,363)(71,111,170, 255,374)(74,115,175,262,383)(76,118,179,268,392)(79,123,187,280,410)(81, 126,191,284,416)(84,131,198,295,428)(85,132,199,297,431)(88,137,206,307, 446)(91,141,212,317,159)(93,144,216,211,315)(98,151,227,338,482)(101,155, 233,347,378)(103,158,237,353,505)(107,165,247,365,519)(109,167,250,369, 525)(112,171,257,376,535)(113,172,259,379,539)(116,176,264,386,549)(119, 180,270,395,560)(121,183,274,401,570)(124,188,282,413,586)(127,192,286, 418,334)(129,194,289,421,597)(133,200,299,433,615)(135,203,303,439,624) (138,207,309,448,635)(139,208,311,451,639)(142,213,319,461,189)(145,217, 324,467,660)(147,220,328,473,267)(149,223,332,476,673)(152,228,340,485, 685)(153,229,342,488,690)(156,234,349,498,705)(161,240,357,510,721)(163, 243,361,514,727)(168,251,371,528,745)(177,265,388,552,698)(178,266,390, 553,776)(181,271,397,563,787)(184,275,403,573,801)(186,278,407,310,449) (190,201,300,435,617)(195,290,298,432,613)(197,293,426,604,842)(204,304, 441,625,864)(205,305,443,627,331)(209,312,453,642,863)(214,320,463,655, 900)(215,321,465,658,904)(218,325,469,662,908)(221,329,474,669,916)(224, 333,478,676,923)(226,336,480,678,926)(230,343,490,693,946)(232,346,494, 699,953)(235,350,500,708,962)(236,351,502,572,799)(238,354,507,716,973) (241,358,512,724,981)(244,362,516,616,855)(246,364,415,589,822)(248,366, 521,734,993)(249,367,522,736,996)(252,341,486,687,938)(254,373,531,750, 893)(256,261,381,542,389)(258,377,537,756,1019)(263,384,546,767,1035) (269,393,557,780,1050)(272,398,565,790,1060)(273,399,567,793,1011)(276, 404,575,804,1074)(279,408,579,810,1080)(281,411,583,814,1085)(283,414, 588,820,337)(285,417,591,825,1097)(287,419,593,828,1099)(288,420,595,831, 1103)(291,423,600,770,1039)(294,427,606,845,803)(296,429,609,848,774) (301,436,619,857,1135)(302,437,621,719,976)(306,444,629,868,1147)(308, 447,633,874,322)(313,454,644,659,905)(316,457,648,890,1173)(318,459,650, 894,1178)(323,466,605,843,1117)(326,470,532,751,442)(327,471,665,912,518) (330,475,671,919,1200)(339,483,682,932,440)(344,491,695,578,808)(348,496, 702,827,675)(352,503,712,968,805)(355,508,718,880,1160)(356,509,720,977, 1262)(359,513,726,983,987)(368,523,738,999,1287)(370,526,742,1004,1293) (372,529,747,1010,1299)(375,533,753,672,920)(380,540,760,409,580)(382, 543,763,1028,1317)(385,547,632,872,1151)(387,550,772,1041,1329)(391,554, 777,1047,1335)(394,558,782,1051,1125)(396,561,785,1029,1318)(400,568,795, 1066,1354)(402,571,798,995,1281)(405,576,806,1076,1361)(406,577,807,1078, 1363)(412,584,816,1088,668)(422,598,835,1107,562)(424,601,837,1109,1396) (425,602,839,1111,1397)(430,610,849,1124,1409)(434,445,630,870,556)(438, 622,861,1139,1419)(450,637,878,1158,1360)(452,640,882,1163,1441)(455,645, 886,704,957)(456,646,887,1170,1450)(458,649,892,1176,1457)(460,651,833, 1106,1393)(462,653,898,1184,1467)(464,656,902,468,661)(472,666,914,1081, 1366)(477,674,922,1203,1490)(479,677,925,1205,1493)(481,679,928,1209, 1498)(484,683,933,1215,1507)(487,688,940,1223,1518)(489,691,944,1228, 1522)(492,696,950,797,1068)(493,697,951,1235,752)(495,700,954,1238,1533) (497,703,956,1240,729)(499,706,960,867,1145)(501,709,964,1246,1544)(504, 713,969,1252,1272)(506,715,972,1256,1552)(511,722,979,869,1148)(515,728, 986,1270,1056)(517,730,988,1271,1564)(520,732,990,1275,1567)(524,739, 1001,1290,1584)(527,743,1006,1296,1016)(530,748,1012,1300,1590)(534,643, 885,1167,1447)(536,755,1017,1304,1595)(538,757,1021,1308,1600)(541,592, 826,1098,1385)(544,764,1030,1320,1607)(545,765,1032,1322,1610)(548,769, 1038,634,875)(551,773,1043,594,829)(555,778,1048,1336,781)(559,783,1053, 1340,1629)(564,788,1057,1345,1634)(566,791,1062,1146,1427)(569,796,813, 1084,1371)(574,802,1073,1292,924)(581,811,762,1026,1315)(582,812,1083, 1369,1659)(585,817,1089,1266,1003)(587,818,1091,1378,1667)(590,823,1095, 1382,1670)(596,832,1105,1391,1677)(599,836,1108,1334,1624)(603,840,1113, 1399,1245)(607,846,1121,1407,1683)(608,847,1123,1192,1476)(611,850,1126, 707,961)(612,851,692,749,1013)(614,853,1130,1411,1643)(618,856,1133,663, 909)(620,858,1137,1417,1693)(623,862,1141,1422,1134)(626,865,1007,1297, 1541)(628,866,1144,1425,1594)(631,871,1149,1169,1449)(636,876,1155,971, 1254)(638,879,1159,1435,1705)(641,883,1164,1443,1236)(647,888,1171,1451, 1319)(652,896,1181,1464,1689)(654,681,930,1211,1501)(657,903,1061,1349, 1094)(664,910,1193,1478,1737)(667,915,1198,1483,1742)(670,917,1186,1104, 1390)(680,929,1210,1278,1570)(684,934,731,989,1273)(686,936,1042,809, 1079)(689,941,1225,1520,1175)(694,947,1232,1527,1772)(701,744,754,1015, 1303)(710,965,1247,1546,1785)(711,966,1248,1548,1787)(714,970,1253,1082, 1367)(717,974,1258,1040,1327)(723,980,955,984,1267)(725,982,1265,1561, 1800)(733,991,1276,1568,1805)(735,994,1280,1571,1537)(737,997,1284,1576, 1815)(740,1002,1291,1585,1822)(741,746,1008,897,1182)(758,1022,1310,1602, 1831)(759,1023,1311,1486,1608)(761,1025,1314,1596,1250)(766,1033,1269, 860,1138)(768,1036,1324,1614,1838)(771,899,1185,1469,1730)(775,1044,1067, 1355,1646)(779,1049,1338,1626,1849)(784,1054,1342,1583,1820)(786,1055, 1330,1620,1844)(789,1058,1347,1637,1261)(792,1063,1351,1642,1856)(794, 1065,1353,1644,1799)(800,1071,844,1118,1404)(815,1086,1373,1662,1871) (819,1092,1379,1668,1874)(821,1093,1380,1208,1497)(824,1077,1362,1654, 1633)(830,1101,1388,873,1152)(834,918,1199,1485,1745)(838,1110,1018,1305, 1597)(841,1114,1401,1157,1434)(852,1128,1410,1686,1027)(854,1131,1413, 1140,1420)(859,1070,1119,1405,1681)(877,1156,939,1221,1515)(881,1161, 1438,1709,1808)(884,1165,1445,1715,1907)(889,1172,1452,1719,1744)(891, 1174,1455,1722,1523)(895,1179,1461,1726,1835)(901,1187,1471,1732,1915) (906,1188,1472,1733,1873)(907,1189,1474,1214,1505)(911,948,1233,1529, 1774)(913,1195,1481,1364,1655)(921,1202,1488,1289,1582)(927,1207,1496, 1326,1617)(931,1212,1503,1641,1855)(935,1217,1510,1760,1897)(937,1219, 1142,1423,1316)(942,1226,1031,1321,1609)(943,1227,1440,1711,1286)(945, 1229,1403,1554,1794)(949,1234,1530,1775,1442)(952,1090,1376,1664,1116) (958,1242,1538,1580,1781)(959,1243,1540,1168,1448)(963,1244,1542,1782, 1845)(967,1249,1295,1343,1356)(975,1259,1556,1716,1753)(978,1263,1558, 1797,1337)(985,1268,1562,1675,1869)(992,1277,1569,1470,1009)(998,1285, 1578,1817,1950)(1000,1288,1581,1819,1127)(1005,1294,1587,1313,1604)(1014, 1301,1592,1487,1746)(1020,1307,1549,1788,1948)(1024,1312,1603,1786,1945) (1034,1323,1612,1430,1699)(1037,1325,1616,1840,1453)(1045,1332,1153,1431, 1700)(1046,1333,1230,1524,1769)(1052,1339,1628,1636,1545)(1059,1348,1639, 1526,1771)(1064,1352,1418,1694,1704)(1069,1357,1648,1623,1374)(1072,1132, 1414,1690,1888)(1075,1359,1651,1459,1460)(1087,1282,1573,1810,1909)(1096, 1383,1671,1876,1983)(1100,1387,1674,1880,1766)(1102,1389,1676,1881,1421) (1112,1398,1365,1656,1866)(1115,1402,1657,1867,1906)(1120,1406,1682,1885, 1468)(1122,1408,1684,1560,1798)(1129,1177,1458,1725,1853)(1136,1415,1691, 1890,1988)(1143,1424,1695,1375,1663)(1150,1428,1611,1837,1770)(1154,1432, 1702,1811,1613)(1162,1439,1710,1902,1547)(1166,1446,1717,1908,1625)(1180, 1462,1543,1783,1701)(1183,1465,1400,1213,1504)(1190,1206,1494,1495,1751) (1191,1475,1735,1917,2001)(1194,1479,1739,1920,1754)(1196,1264,1559,1532, 1776)(1197,1482,1741,1921,1412)(1201,1394,1679,1883,1650)(1204,1491,1749, 1792,1952)(1216,1508,1759,1239,1534)(1218,1511,1456,1723,1279)(1220,1513, 1762,1492,1750)(1222,1516,1572,1809,1958)(1224,1519,1765,1777,1938)(1231, 1525,1652,1535,1298)(1237,1531,1473,1309,1601)(1241,1536,1779,1673,1879) (1251,1550,1790,1949,1887)(1255,1551,1791,1951,1843)(1257,1553,1793,1437, 1707)(1260,1557,1796,1517,1764)(1274,1565,1713,1905,1821)(1283,1574,1812, 1960,2012)(1302,1593,1489,1747,1922)(1306,1598,1829,1892,1969)(1328,1618, 1841,1757,1926)(1331,1621,1846,1901,1995)(1341,1630,1631,1687,1768)(1344, 1632,1851,1975,1963)(1346,1635,1852,1463,1500)(1350,1640,1854,1528,1773) (1358,1649,1514,1763,1740)(1368,1658,1868,1965,1872)(1370,1660,1731,1914, 1429)(1372,1661,1454,1720,1910)(1377,1665,1619,1842,1509)(1381,1669,1875, 1982,1999)(1384,1672,1878,1981,1980)(1386,1645,1858,1976,2016)(1392,1678, 1882,1936,1666)(1395,1588,1824,1968,2013)(1416,1692,1891,1627,1615)(1426, 1696,1688,1806,1947)(1433,1703,1712,1904,1727)(1436,1706,1736,1918,1923) (1444,1714,1789,1480,1477)(1466,1728,1913,1946,1937)(1484,1743,1756,1925, 2000)(1499,1591,1827,1972,1830)(1502,1755,1924,2002,1599)(1506,1758,1928, 2004,1857)(1512,1761,1930,1575,1813)(1521,1767,1863,1979,1836)(1539,1780, 1941,1996,2015)(1555,1752,1877,1832,1959)(1563,1801,1605,1833,1973)(1566, 1802,1954,1729,1734)(1577,1816,1964,1927,1966)(1579,1818,1638,1807,1956) (1586,1823,1685,1886,1986)(1589,1825,1970,2014,2021)(1606,1834,1708,1900, 1989)(1622,1847,1974,1778,1939)(1647,1860,1848,1795,1748)(1653,1862,1978, 2017,1718)(1680,1884,1814,1962,1828)(1697,1895,1865,1839,1967)(1698,1896, 1985,1894,1990)(1721,1911,1903,1784,1861)(1724,1912,1998,1933,1991)(1738, 1899,1993,1957,2011)(1803,1955,1935,1940,2007)(1804,1826,1971,1984,1870) (1850,1931,1961,1953,1893)(1859,1977,1997,2018,2023)(1864,1929,1898,1992, 1919)(1889,1916,1942,2008,2022)(1932,2005,2020,1944,2010)(1934,1994,1943, 2009,2006)(1987,2019,2024,2025,2003);