using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        var nums = new int[] { 1411,

1802,

1773,

1775,

1442,

1471,

1048,

1403,

1881,

1930,

1710,

1717,

685,

1255,

1451,

1870,

208,

1725,

1879,

143,

1372,

1726,

1357,

1624,

1378,

1993,

1721,

1712,

1867,

1355,

1743,

1942,

114,

407,

1892,

1937,

2001,

1466,

1461,

1770,

1441,

1410,

1915,

1482,

1512,

1631,

1954,

1632,

1788,

1971,

1989,

1427,

1684,

1749,

1795,

1839,

1358,

1354,

1591,

1924,

1456,

2002,

1746,

1323,

1946,

1889,

296,

1908,

1959,

1944,

1655,

1602,

1768,

1666,

1465,

1782,

1739,

1472,

1576,

645,

1496,

1538,

1761,

1353,

1639,

1904,

1765,

1519,

1948,

1900,

1376,

1918,

1950,

667,

1976,

1925,

1939,

1319,

1895,

1510,

1480,

735,

1674,

1997,

1868,

1728,

1893,

1500,

1363,

1840,

1905,

1361,

1894,

1558,

1369,

1922,

1367,

1463,

1365,

1504,

1898,

1343,

1436,

1700,

1911,

1811,

1829,

1984,

1444,

1806,

1455,

1778,

1835,

1817,

1668,

1907,

1748,

2007,

1534,

1269,

1473,

1572,

2006,

1651,

1853,

1943,

1968,

1969,

1437,

1692,

1955,

1964,

1821,

1805,

1999,

1614,

1754,

1888,

1832,

1623,

1723,

1678,

2008,

1819,

1595,

1972,

1229,

1703,

1762,

1818,

1062,

1599,

1996,

2000,

1960,

1927,

1407,

1414,

1923,

1685,

1998,

1497,

1687,

1416,

1757,

1470,

1810,

2010,

1553,

1379,

1495,

1565,

1796,

2004,

1899,

2009,

1395,

1388,

1902,

1741};

​

        var complements = new Dictionary<int, int>();

        foreach (var n in nums)

        {

            if (complements.TryGetValue(n, out var c))

            {

                Console.WriteLine($"{n}*{c}={n * c}");

            }

            complements[2020 - n] = n;

        }

    }

}