import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.io.Closeable;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws Exception {
        Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 27);
        thread.start();
        thread.join();
    }

    static class TaskAdapter implements Runnable {
        @Override
        public void run() {
            InputStream inputStream = System.in;
            OutputStream outputStream = System.out;
            FastInput in = new FastInput(inputStream);
            FastOutput out = new FastOutput(outputStream);
            BSumANDSubarrays solver = new BSumANDSubarrays();
            solver.solve(1, in, out);
            out.close();
        }
    }

    static class BSumANDSubarrays {
        public void solve(int testNumber, FastInput in, FastOutput out) {
            int n = in.readInt();
            int k = in.readInt();
            long[] a = new long[n];
            for (int i = 0; i < n; i++) {
                a[i] = in.readInt();
            }
            LongPreSum ps = new LongPreSum(a);
            LongList list = new LongList(n * n / 2);
            for (int i = 0; i < n; i++) {
                for (int j = i; j < n; j++) {
                    list.add(ps.intervalSum(i, j));
                }
            }
            long[] data = list.toArray();
            int m = data.length;
            long mask = 0;
            for (int i = 60; i >= 0; i--) {
                long test = Bits.setBit(mask, i, true);
                int cnt = 0;
                for (long x : data) {
                    if (Bits.subset(test, x)) {
                        cnt++;
                    }
                }

                if (cnt >= k) {
                    mask = test;
                }
            }

            out.println(mask);
        }

    }

    static class LongList implements Cloneable {
        private int size;
        private int cap;
        private long[] data;
        private static final long[] EMPTY = new long[0];

        public LongList(int cap) {
            this.cap = cap;
            if (cap == 0) {
                data = EMPTY;
            } else {
                data = new long[cap];
            }
        }

        public LongList(LongList list) {
            this.size = list.size;
            this.cap = list.cap;
            this.data = Arrays.copyOf(list.data, size);
        }

        public LongList() {
            this(0);
        }

        public void ensureSpace(int req) {
            if (req > cap) {
                while (cap < req) {
                    cap = Math.max(cap + 10, 2 * cap);
                }
                data = Arrays.copyOf(data, cap);
            }
        }

        public void add(long x) {
            ensureSpace(size + 1);
            data[size++] = x;
        }

        public void addAll(long[] x, int offset, int len) {
            ensureSpace(size + len);
            System.arraycopy(x, offset, data, size, len);
            size += len;
        }

        public void addAll(LongList list) {
            addAll(list.data, 0, list.size);
        }

        public long[] toArray() {
            return Arrays.copyOf(data, size);
        }

        public String toString() {
            return Arrays.toString(toArray());
        }

        public boolean equals(Object obj) {
            if (!(obj instanceof LongList)) {
                return false;
            }
            LongList other = (LongList) obj;
            return SequenceUtils.equal(data, 0, size - 1, other.data, 0, other.size - 1);
        }

        public int hashCode() {
            int h = 1;
            for (int i = 0; i < size; i++) {
                h = h * 31 + Long.hashCode(data[i]);
            }
            return h;
        }

        public LongList clone() {
            LongList ans = new LongList();
            ans.addAll(this);
            return ans;
        }

    }

    static class FastInput {
        private final InputStream is;
        private byte[] buf = new byte[1 << 20];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastInput(InputStream is) {
            this.is = is;
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    bufLen = -1;
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

    }

    static class Bits {
        private Bits() {
        }

        public static long setBit(long x, int i, boolean v) {
            if (v) {
                x |= 1L << i;
            } else {
                x &= ~(1L << i);
            }
            return x;
        }

        public static boolean subset(long x, long y) {
            return intersect(x, y) == x;
        }

        public static long intersect(long x, long y) {
            return x & y;
        }

    }

    static class LongPreSum {
        private long[] pre;
        private int n;

        public LongPreSum(int n) {
            pre = new long[n];
        }

        public void populate(long[] a) {
            n = a.length;
            pre[0] = a[0];
            for (int i = 1; i < n; i++) {
                pre[i] = pre[i - 1] + a[i];
            }
        }

        public LongPreSum(long[] a) {
            this(a.length);
            populate(a);
        }

        public long intervalSum(int l, int r) {
            return prefix(r) - prefix(l - 1);
        }

        public long prefix(int i) {
            if (i < 0) {
                return 0;
            }
            return pre[Math.min(i, n - 1)];
        }

    }

    static class SequenceUtils {
        public static boolean equal(long[] a, int al, int ar, long[] b, int bl, int br) {
            if ((ar - al) != (br - bl)) {
                return false;
            }
            for (int i = al, j = bl; i <= ar; i++, j++) {
                if (a[i] != b[j]) {
                    return false;
                }
            }
            return true;
        }

    }

    static class FastOutput implements AutoCloseable, Closeable, Appendable {
        private StringBuilder cache = new StringBuilder(10 << 20);
        private final Writer os;

        public FastOutput append(CharSequence csq) {
            cache.append(csq);
            return this;
        }

        public FastOutput append(CharSequence csq, int start, int end) {
            cache.append(csq, start, end);
            return this;
        }

        public FastOutput(Writer os) {
            this.os = os;
        }

        public FastOutput(OutputStream os) {
            this(new OutputStreamWriter(os));
        }

        public FastOutput append(char c) {
            cache.append(c);
            return this;
        }

        public FastOutput append(long c) {
            cache.append(c);
            return this;
        }

        public FastOutput println(long c) {
            return append(c).println();
        }

        public FastOutput println() {
            cache.append(System.lineSeparator());
            return this;
        }

        public FastOutput flush() {
            try {
                os.append(cache);
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
            return this;
        }

        public void close() {
            flush();
            try {
                os.close();
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        public String toString() {
            return cache.toString();
        }

    }
}



Measured memory_bytes: 69376