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

alias sread = () => readln.chomp();
ulong bignum = 1_000_000_007;
alias Pair = Tuple!(long, "begin", long, "end");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

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;
    }
}

void main()
{
    long n, k;
    scan(n, k);
    auto ary = aryread();
    auto beautiful = new long[](0);
    foreach (i; 0 .. n)
    {
        foreach (j; i + 1 .. n + 1)
        {
            beautiful ~= ary[i .. j].sum();
        }
    }
    long max_beauty = beautiful.reduce!(max), m = 1;
    while (max_beauty > 0)
    {
        m++;
        max_beauty /= 2;
    }
    long ans;
    foreach_reverse (i; 0 .. m)
    {
        long count, power = 1 << i;
        foreach (e; beautiful)
        {
            if (((ans + power) & e) == (ans + power))
                count++;
        }
        if (count >= k)
            ans += power;
    }
    ans.writeln();
}