import core.bitop, std.algorithm, std.ascii, std.bigint, std.conv, std.math,
    std.functional, std.numeric, std.range, std.stdio, std.string, std.random,
    std.typecons, std.container, std.format;

// dfmt off
T lread(T = long)(){return readln.chomp.to!T();}
T[] lreads(T = long)(long n){return generate(()=>readln.chomp.to!T()).take(n).array();}
T[] aryread(T = long)(){return readln.split.to!(T[])();}
void scan(TList...)(ref TList Args){auto line = readln.split();
foreach (i, T; TList){T val = line[i].to!(T);Args[i] = val;}}
alias sread = () => readln.chomp();enum MOD = 10 ^^ 9 + 7;
alias PQueue(T, alias less = "a<b") = BinaryHeap!(Array!T, less);
// dfmt on

void main()
{
    long N;
    ulong K;
    scan(N, K);
    auto A = aryread!ulong();
    auto dp = new ulong[][](2, 65);
    foreach (i; 0 .. 64)
    {
        ulong bitx = (K >> (63 - i)) & 1;
        ulong[2] cnt;
        foreach (a; A)
        {
            ulong bita = (a >> (63 - i)) & 1;
            cnt[bita]++;
        }
        if (bitx == 0)
        {
            dp[0][i + 1] = (dp[0][i] << 1) + cnt[1];
            if ((1 << (63 - i)) < K)
                dp[1][i + 1] = (dp[1][i] << 1) + max(cnt[0], cnt[1]);
            continue;
        }
        if (bitx == 1)
        {
            dp[0][i + 1] = (dp[0][i] << 1) + cnt[0];
            dp[1][i + 1] = max((dp[1][i] << 1) + max(cnt[0], cnt[1]), (dp[0][i] << 1) + cnt[1]);
            continue;
        }
        assert(0);
    }
    writeln(max(dp[1][$ - 1], dp[0][$ - 1]));
}
