Mr Keks is a typical white-collar in Byteland.

He has a bookshelf in his office with some books on it, each book has an integer positive price.

Mr Keks defines the value of a shelf as the sum of books prices on it. 

Miraculously, Mr Keks was promoted and now he is moving into a new office.

He learned that in the new office he will have not a single bookshelf, but exactly $k$ bookshelves. He decided that the beauty of the $k$ shelves is the bitwise AND of the values of all the shelves.

He also decided that he won't spend time on reordering the books, so he will place several first books on the first shelf, several next books on the next shelf and so on. Of course, he will place at least one book on each shelf. This way he will put all his books on $k$ shelves in such a way that the beauty of the shelves is as large as possible. Compute this maximum possible beauty.


-----Input-----

The first line contains two integers $n$ and $k$ ($1 \leq k \leq n \leq 50$) — the number of books and the number of shelves in the new office.

The second line contains $n$ integers $a_1, a_2, \ldots a_n$, ($0 < a_i < 2^{50}$) — the prices of the books in the order they stand on the old shelf.


-----Output-----

Print the maximum possible beauty of $k$ shelves in the new office.


-----Examples-----
Input
10 4
9 14 28 1 7 13 15 29 2 31

Output
24

Input
7 3
3 14 15 92 65 35 89

Output
64



-----Note-----

In the first example you can split the books as follows:

$$(9 + 14 + 28 + 1 + 7) \& (13 + 15) \& (29 + 2) \& (31) = 24.$$

In the second example you can split the books as follows:

$$(3 + 14 + 15 + 92) \& (65) \& (35 + 89) = 64.$$

Difficulty: HARD
Tags: Dynamic programming

Bit manipulation

Greedy algorithms
Skill types: Dynamic programming

Bit manipulation

Greedy algorithms

Starter code:

Solutions:
import time

def getIntList():
	return list(map(int, input().split()))

def getTransIntList(n):
	first = getIntList()
	m = len(first)
	result = [[0] * n for _ in range(m)]
	for i in range(m):
		result[i][0] = first[i]
	for j in range(1, n):
		curr = getIntList()
		for i in range(m):
			result[i][j] = curr[i]
	return result
(n, k) = getIntList()
a = getIntList()
sums = [[0] * (n + 1) for _ in range(n + 1)]
for i in range(n):
	for j in range(i + 1, n + 1):
		sums[i][j] = sums[i][j - 1] + a[j - 1]

class SearchProblem:

	def __init__(self, a, n, k, tiLim):
		self.a = a
		self.n = n
		self.k = k
		self.maxResult = 0
		self.tiLim = time.time() + tiLim

	def search(self, currResult, currIndex, currLines):
		if time.time() > self.tiLim:
			return
		if currLines > 0 and currResult <= self.maxResult:
			return
		if currLines == self.k - 1:
			lastSum = sums[currIndex][self.n]
			currResult = currResult & lastSum
			if currResult > self.maxResult:
				self.maxResult = currResult
		for nextIndex in range(currIndex + 1, self.n + 1):
			currSum = sums[currIndex][nextIndex]
			if currLines == 0:
				nextResult = currSum
			else:
				nextResult = currResult & currSum
			self.search(nextResult, nextIndex, currLines + 1)
		flag = True
		if time.time() > self.tiLim:
			flag = False
		return (self.maxResult, flag)
upLim = [[0] * (n + 1) for _ in range(k + 1)]
for i in range(1, k + 1):
	if i == 1:
		for j in range(0, n):
			upLim[i][j] = sums[j][n]
	else:
		for j in range(n - i, -1, -1):
			upLim[i][j] = 0
			for j1 in range(j + 1, n):
				curr = min(sums[j][j1], upLim[i - 1][j1])
				upLim[i][j] = max(upLim[i][j], curr)

def solve():
	problem = SearchProblem(a, n, k, 0.1)
	if k == 1:
		return sum(a)
	(maxResult, solved) = problem.search(0, 0, 0)
	if solved:
		return maxResult
	results = [[set() for _ in range(n + 1)] for _ in range(k + 1)]
	for i in range(1, n + 1):
		for firstIndexSum in range(0, i):
			currSum = sums[firstIndexSum][i]
			if firstIndexSum == 0:
				if currSum > maxResult:
					results[1][i].add(currSum)
				if k == 2:
					lastSum = sums[i][n]
					currResult = currSum & lastSum
					if currResult > maxResult:
						maxResult = currResult
						for lines1 in range(k):
							for j in range(n):
								results[lines1][j] = {r for r in results[lines1][j] if r >= maxResult}
			else:
				for lines in range(k):
					for prevSum in results[lines][firstIndexSum]:
						fullSum = prevSum & currSum
						currLines = lines + 1
						if currLines == k - 1:
							lastSum = sums[i][n]
							currResult = fullSum & lastSum
							if currResult > maxResult:
								maxResult = currResult
								for lines1 in range(k):
									for j in range(n):
										results[lines1][j] = {r for r in results[lines1][j] if r >= maxResult}
						if upLim[k - currLines][i] <= maxResult:
							continue
						if fullSum > maxResult:
							results[currLines][i].add(fullSum)
	return maxResult
print(solve())


import os
import sys
from io import BytesIO, IOBase
BUFSIZE = 8192

class FastIO(IOBase):
	newlines = 0

	def __init__(self, file):
		self._fd = file.fileno()
		self.buffer = BytesIO()
		self.writable = 'x' in file.mode or 'r' not in file.mode
		self.write = self.buffer.write if self.writable else None

	def read(self):
		while True:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			if not b:
				break
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines = 0
		return self.buffer.read()

	def readline(self):
		while self.newlines == 0:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			self.newlines = b.count(b'\n') + (not b)
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines -= 1
		return self.buffer.readline()

	def flush(self):
		if self.writable:
			os.write(self._fd, self.buffer.getvalue())
			(self.buffer.truncate(0), self.buffer.seek(0))

class IOWrapper(IOBase):

	def __init__(self, file):
		self.buffer = FastIO(file)
		self.flush = self.buffer.flush
		self.writable = self.buffer.writable
		self.write = lambda s: self.buffer.write(s.encode('ascii'))
		self.read = lambda : self.buffer.read().decode('ascii')
		self.readline = lambda : self.buffer.readline().decode('ascii')
(sys.stdin, sys.stdout) = (IOWrapper(sys.stdin), IOWrapper(sys.stdout))
input = lambda : sys.stdin.readline().rstrip('\r\n')
from math import factorial
from collections import Counter, defaultdict, deque
from heapq import heapify, heappop, heappush

def RL():
	return map(int, sys.stdin.readline().rstrip().split())

def RLL():
	return list(map(int, sys.stdin.readline().rstrip().split()))

def N():
	return int(input())

def comb(n, m):
	return factorial(n) / (factorial(m) * factorial(n - m)) if n >= m else 0

def perm(n, m):
	return factorial(n) // factorial(n - m) if n >= m else 0

def mdis(x1, y1, x2, y2):
	return abs(x1 - x2) + abs(y1 - y2)
mod = 998244353
INF = float('inf')

def main():
	(n, k) = RL()
	arr = RLL()

	def dpf(num):
		dp = [[0] * (k + 1) for _ in range(n + 1)]
		dp[0][0] = 1
		for i in range(1, n + 1):
			for j in range(1, k + 1):
				now = 0
				for l in range(i, j - 2, -1):
					now += arr[l - 1]
					dp[i][j] |= dp[l - 1][j - 1] and now & num == num
		return dp[-1][-1]
	res = 0
	inc = 0
	for i in range(55, -1, -1):
		if dpf(inc + (1 << i)):
			inc += 1 << i
		res = max(res, inc)
	print(res)
main()


import os
import sys
import math
from io import BytesIO, IOBase
import io
from fractions import Fraction
import collections
from itertools import permutations
from collections import defaultdict
from collections import deque
from collections import Counter
import threading
BUFSIZE = 8192

class FastIO(IOBase):
	newlines = 0

	def __init__(self, file):
		self._fd = file.fileno()
		self.buffer = BytesIO()
		self.writable = 'x' in file.mode or 'r' not in file.mode
		self.write = self.buffer.write if self.writable else None

	def read(self):
		while True:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			if not b:
				break
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines = 0
		return self.buffer.read()

	def readline(self):
		while self.newlines == 0:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			self.newlines = b.count(b'\n') + (not b)
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines -= 1
		return self.buffer.readline()

	def flush(self):
		if self.writable:
			os.write(self._fd, self.buffer.getvalue())
			(self.buffer.truncate(0), self.buffer.seek(0))

class IOWrapper(IOBase):

	def __init__(self, file):
		self.buffer = FastIO(file)
		self.flush = self.buffer.flush
		self.writable = self.buffer.writable
		self.write = lambda s: self.buffer.write(s.encode('ascii'))
		self.read = lambda : self.buffer.read().decode('ascii')
		self.readline = lambda : self.buffer.readline().decode('ascii')
(sys.stdin, sys.stdout) = (IOWrapper(sys.stdin), IOWrapper(sys.stdout))
input = lambda : sys.stdin.readline().rstrip('\r\n')

class SegmentTree:

	def __init__(self, data, default=0, func=lambda a, b: max(a, b)):
		self._default = default
		self._func = func
		self._len = len(data)
		self._size = _size = 1 << (self._len - 1).bit_length()
		self.data = [default] * (2 * _size)
		self.data[_size:_size + self._len] = data
		for i in reversed(range(_size)):
			self.data[i] = func(self.data[i + i], self.data[i + i + 1])

	def __delitem__(self, idx):
		self[idx] = self._default

	def __getitem__(self, idx):
		return self.data[idx + self._size]

	def __setitem__(self, idx, value):
		idx += self._size
		self.data[idx] = value
		idx >>= 1
		while idx:
			self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
			idx >>= 1

	def __len__(self):
		return self._len

	def query(self, start, stop):
		if start == stop:
			return self.__getitem__(start)
		stop += 1
		start += self._size
		stop += self._size
		res = self._default
		while start < stop:
			if start & 1:
				res = self._func(res, self.data[start])
				start += 1
			if stop & 1:
				stop -= 1
				res = self._func(res, self.data[stop])
			start >>= 1
			stop >>= 1
		return res

	def __repr__(self):
		return 'SegmentTree({0})'.format(self.data)

class SegmentTree1:

	def __init__(self, data, default=0, func=lambda a, b: a + b):
		self._default = default
		self._func = func
		self._len = len(data)
		self._size = _size = 1 << (self._len - 1).bit_length()
		self.data = [default] * (2 * _size)
		self.data[_size:_size + self._len] = data
		for i in reversed(range(_size)):
			self.data[i] = func(self.data[i + i], self.data[i + i + 1])

	def __delitem__(self, idx):
		self[idx] = self._default

	def __getitem__(self, idx):
		return self.data[idx + self._size]

	def __setitem__(self, idx, value):
		idx += self._size
		self.data[idx] = value
		idx >>= 1
		while idx:
			self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
			idx >>= 1

	def __len__(self):
		return self._len

	def query(self, start, stop):
		if start == stop:
			return self.__getitem__(start)
		stop += 1
		start += self._size
		stop += self._size
		res = self._default
		while start < stop:
			if start & 1:
				res = self._func(res, self.data[start])
				start += 1
			if stop & 1:
				stop -= 1
				res = self._func(res, self.data[stop])
			start >>= 1
			stop >>= 1
		return res

	def __repr__(self):
		return 'SegmentTree({0})'.format(self.data)
MOD = 10 ** 9 + 7

class Factorial:

	def __init__(self, MOD):
		self.MOD = MOD
		self.factorials = [1, 1]
		self.invModulos = [0, 1]
		self.invFactorial_ = [1, 1]

	def calc(self, n):
		if n <= -1:
			print('Invalid argument to calculate n!')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		if n < len(self.factorials):
			return self.factorials[n]
		nextArr = [0] * (n + 1 - len(self.factorials))
		initialI = len(self.factorials)
		prev = self.factorials[-1]
		m = self.MOD
		for i in range(initialI, n + 1):
			prev = nextArr[i - initialI] = prev * i % m
		self.factorials += nextArr
		return self.factorials[n]

	def inv(self, n):
		if n <= -1:
			print('Invalid argument to calculate n^(-1)')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		p = self.MOD
		pi = n % p
		if pi < len(self.invModulos):
			return self.invModulos[pi]
		nextArr = [0] * (n + 1 - len(self.invModulos))
		initialI = len(self.invModulos)
		for i in range(initialI, min(p, n + 1)):
			next = -self.invModulos[p % i] * (p // i) % p
			self.invModulos.append(next)
		return self.invModulos[pi]

	def invFactorial(self, n):
		if n <= -1:
			print('Invalid argument to calculate (n^(-1))!')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		if n < len(self.invFactorial_):
			return self.invFactorial_[n]
		self.inv(n)
		nextArr = [0] * (n + 1 - len(self.invFactorial_))
		initialI = len(self.invFactorial_)
		prev = self.invFactorial_[-1]
		p = self.MOD
		for i in range(initialI, n + 1):
			prev = nextArr[i - initialI] = prev * self.invModulos[i % p] % p
		self.invFactorial_ += nextArr
		return self.invFactorial_[n]

class Combination:

	def __init__(self, MOD):
		self.MOD = MOD
		self.factorial = Factorial(MOD)

	def ncr(self, n, k):
		if k < 0 or n < k:
			return 0
		k = min(k, n - k)
		f = self.factorial
		return f.calc(n) * f.invFactorial(max(n - k, k)) * f.invFactorial(min(k, n - k)) % self.MOD
mod = 10 ** 9 + 7
omod = 998244353
prime = [True for i in range(10001)]
prime[0] = prime[1] = False

def SieveOfEratosthenes(n=10000):
	p = 2
	c = 0
	while p <= n:
		if prime[p] == True:
			c += 1
			for i in range(p, n + 1, p):
				prime[i] = False
		p += 1

class DSU:

	def __init__(self, R, C):
		self.par = range(R * C + 1)
		self.rnk = [0] * (R * C + 1)
		self.sz = [1] * (R * C + 1)

	def find(self, x):
		if self.par[x] != x:
			self.par[x] = self.find(self.par[x])
		return self.par[x]

	def union(self, x, y):
		(xr, yr) = (self.find(x), self.find(y))
		if xr == yr:
			return
		if self.rnk[xr] < self.rnk[yr]:
			(xr, yr) = (yr, xr)
		if self.rnk[xr] == self.rnk[yr]:
			self.rnk[xr] += 1
		self.par[yr] = xr
		self.sz[xr] += self.sz[yr]

	def size(self, x):
		return self.sz[self.find(x)]

	def top(self):
		return self.size(len(self.sz) - 1) - 1

class LazySegTree:

	def __init__(self, _op, _e, _mapping, _composition, _id, v):

		def set(p, x):
			assert 0 <= p < _n
			p += _size
			for i in range(_log, 0, -1):
				_push(p >> i)
			_d[p] = x
			for i in range(1, _log + 1):
				_update(p >> i)

		def get(p):
			assert 0 <= p < _n
			p += _size
			for i in range(_log, 0, -1):
				_push(p >> i)
			return _d[p]

		def prod(l, r):
			assert 0 <= l <= r <= _n
			if l == r:
				return _e
			l += _size
			r += _size
			for i in range(_log, 0, -1):
				if l >> i << i != l:
					_push(l >> i)
				if r >> i << i != r:
					_push(r >> i)
			sml = _e
			smr = _e
			while l < r:
				if l & 1:
					sml = _op(sml, _d[l])
					l += 1
				if r & 1:
					r -= 1
					smr = _op(_d[r], smr)
				l >>= 1
				r >>= 1
			return _op(sml, smr)

		def apply(l, r, f):
			assert 0 <= l <= r <= _n
			if l == r:
				return
			l += _size
			r += _size
			for i in range(_log, 0, -1):
				if l >> i << i != l:
					_push(l >> i)
				if r >> i << i != r:
					_push(r - 1 >> i)
			l2 = l
			r2 = r
			while l < r:
				if l & 1:
					_all_apply(l, f)
					l += 1
				if r & 1:
					r -= 1
					_all_apply(r, f)
				l >>= 1
				r >>= 1
			l = l2
			r = r2
			for i in range(1, _log + 1):
				if l >> i << i != l:
					_update(l >> i)
				if r >> i << i != r:
					_update(r - 1 >> i)

		def _update(k):
			_d[k] = _op(_d[2 * k], _d[2 * k + 1])

		def _all_apply(k, f):
			_d[k] = _mapping(f, _d[k])
			if k < _size:
				_lz[k] = _composition(f, _lz[k])

		def _push(k):
			_all_apply(2 * k, _lz[k])
			_all_apply(2 * k + 1, _lz[k])
			_lz[k] = _id
		_n = len(v)
		_log = _n.bit_length()
		_size = 1 << _log
		_d = [_e] * (2 * _size)
		_lz = [_id] * _size
		for i in range(_n):
			_d[_size + i] = v[i]
		for i in range(_size - 1, 0, -1):
			_update(i)
		self.set = set
		self.get = get
		self.prod = prod
		self.apply = apply
MIL = 1 << 20

def makeNode(total, count):
	return total * MIL + count

def getTotal(node):
	return math.floor(node / MIL)

def getCount(node):
	return node - getTotal(node) * MIL
nodeIdentity = makeNode(0.0, 0.0)

def nodeOp(node1, node2):
	return node1 + node2
	return makeNode(getTotal(node1) + getTotal(node2), getCount(node1) + getCount(node2))
identityMapping = -1

def mapping(tag, node):
	if tag == identityMapping:
		return node
	count = getCount(node)
	return makeNode(tag * count, count)

def composition(mapping1, mapping2):
	return mapping1 if mapping1 != identityMapping else mapping2

def memodict(f):

	class memodict(dict):

		def __missing__(self, key):
			ret = self[key] = f(key)
			return ret
	return memodict().__getitem__

def pollard_rho(n):
	if n & 1 == 0:
		return 2
	if n % 3 == 0:
		return 3
	s = (n - 1 & 1 - n).bit_length() - 1
	d = n >> s
	for a in [2, 325, 9375, 28178, 450775, 9780504, 1795265022]:
		p = pow(a, d, n)
		if p == 1 or p == n - 1 or a % n == 0:
			continue
		for _ in range(s):
			prev = p
			p = p * p % n
			if p == 1:
				return math.gcd(prev - 1, n)
			if p == n - 1:
				break
		else:
			for i in range(2, n):
				(x, y) = (i, (i * i + 1) % n)
				f = math.gcd(abs(x - y), n)
				while f == 1:
					(x, y) = ((x * x + 1) % n, (y * y + 1) % n)
					y = (y * y + 1) % n
					f = math.gcd(abs(x - y), n)
				if f != n:
					return f
	return n

@memodict
def prime_factors(n):
	if n <= 1:
		return Counter()
	f = pollard_rho(n)
	return Counter([n]) if f == n else prime_factors(f) + prime_factors(n // f)

def distinct_factors(n):
	factors = [1]
	for (p, exp) in prime_factors(n).items():
		factors += [p ** i * factor for factor in factors for i in range(1, exp + 1)]
	return factors

def all_factors(n):
	(small, large) = ([], [])
	for i in range(1, int(n ** 0.5) + 1, 2 if n & 1 else 1):
		if not n % i:
			small.append(i)
			large.append(n // i)
	if small[-1] == large[-1]:
		large.pop()
	large.reverse()
	small.extend(large)
	return small

def binarySearch(arr, n, i, key):
	left = 0
	right = n - 1
	mid = 0
	res = n
	while left <= right:
		mid = (right + left) // 2
		if arr[mid][i] > key:
			res = mid
			right = mid - 1
		else:
			left = mid + 1
	return res

def binarySearch1(arr, n, i, key):
	left = 0
	right = n - 1
	mid = 0
	res = -1
	while left <= right:
		mid = (right + left) // 2
		if arr[mid][i] > key:
			right = mid - 1
		else:
			res = mid
			left = mid + 1
	return res
(n, k) = map(int, input().split())
l = list(map(int, input().split()))
s = [0] * (n + 1)
for i in range(1, n + 1):
	s[i] = s[i - 1] + l[i - 1]

def check(x):
	dp = [[0 for i in range(k + 1)] for j in range(n + 1)]
	dp[0][0] = 1
	for i in range(1, n + 1):
		for j in range(1, min(i, k) + 1):
			for h in range(i - 1, -1, -1):
				cur = s[i] - s[h]
				if cur & x == x:
					dp[i][j] = max(dp[i][j], dp[h][j - 1])
	return dp[n][k]
temp = 0
cou = 2 ** 57
for i in range(57, -1, -1):
	temp ^= cou
	if check(temp):
		ans = temp
	else:
		temp ^= cou
		ans = temp
	cou //= 2
print(ans)


3.7
import sys
(n, k) = [int(x) for x in input().split()]
a = [int(x) for x in input().split()]
cur = 0

def is_submask(n, mask):
	return n & mask == mask

def f(mask):
	s = [[False for j in range(n)] for i in range(n)]
	for l in range(n):
		cur = 0
		for r in range(l, n):
			cur += a[r]
			s[l][r] = is_submask(cur, mask)
	dp = [[False for j in range(n)] for i in range(k)]
	dp[0] = s[0][:]
	for k1 in range(1, k):
		for r in range(n):
			for l in range(1, r + 1):
				dp[k1][r] |= dp[k1 - 1][l - 1] & s[l][r]
	return dp[k - 1][n - 1]
cur = 0
for i in range(56, -1, -1):
	if f(cur + 2 ** i):
		cur += 2 ** i
print(cur)


(n, k) = map(int, input().split())
a = list(map(int, input().split()))
a_sum = [0]
for i in range(n):
	a_sum.append(a_sum[-1] + a[i])
a = [0] + a

def get(i, j):
	assert 0 <= i <= j <= n
	if i > 0:
		return a_sum[j] - a_sum[i - 1]
	else:
		return a_sum[j]
ans = 0
nowmax = 0
for bit in range(60, -1, -1):
	tmpmax = nowmax + (1 << bit)
	dp = [[0] * (n + 10) for i in range(n + 10)]
	dp[0][0] = tmpmax
	for pos in range(1, n + 1):
		for div in range(1, k + 1):
			for l in range(1, pos + 1):
				dp[pos][div] = max(dp[pos][div], dp[pos - l][div - 1] & get(pos - l + 1, pos) & tmpmax)
	if dp[n][k] == tmpmax:
		nowmax += 1 << bit
print(nowmax)


[n, k] = [int(x) for x in input().split()]
sum = [int(x) for x in input().split()]
for i in range(1, n):
	sum[i] += sum[i - 1]

def check(mask, all):
	dp = [[False for j in range(n)] for i in range(k)]
	for i in range(n):
		dp[0][i] = sum[i] & all & mask == mask
	for i in range(1, k):
		for j in range(n):
			dp[i][j] = any((dp[i - 1][p] and sum[j] - sum[p] & all & mask == mask for p in range(0, j)))
	return dp[k - 1][n - 1]
ans = 0
for i in range(60, -1, -1):
	if check(ans | 1 << i, ~((1 << i) - 1)):
		ans |= 1 << i
print(ans)


import os, sys
from io import BytesIO, IOBase

def check(trans, k, n):
	dp = [[0] * (k + 1) for _ in range(n + 1)]
	dp[0][0] = 1
	for i in range(n):
		for y in range(k):
			if not dp[i][y]:
				continue
			for x in trans[i]:
				dp[x][y + 1] = 1
	return dp[n][k]

def main():
	(n, k) = map(int, input().split())
	a = list(map(int, input().split()))
	(ans, de, val) = (0, [], 1 << 60)
	for i in range(59, -1, -1):
		trans = [[] for _ in range(n)]
		val >>= 1
		for j in range(n):
			su = 0
			for l in range(j, n):
				su += a[l]
				fl = 1
				for z in de:
					if not su & z:
						fl = 0
						break
				if not fl or not su & val:
					continue
				trans[j].append(l + 1)
		if check(trans, k, n):
			ans += val
			de.append(val)
	print(ans)
BUFSIZE = 8192

class FastIO(IOBase):
	newlines = 0

	def __init__(self, file):
		self._fd = file.fileno()
		self.buffer = BytesIO()
		self.writable = 'x' in file.mode or 'r' not in file.mode
		self.write = self.buffer.write if self.writable else None

	def read(self):
		while True:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			if not b:
				break
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines = 0
		return self.buffer.read()

	def readline(self):
		while self.newlines == 0:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			self.newlines = b.count(b'\n') + (not b)
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines -= 1
		return self.buffer.readline()

	def flush(self):
		if self.writable:
			os.write(self._fd, self.buffer.getvalue())
			(self.buffer.truncate(0), self.buffer.seek(0))

class IOWrapper(IOBase):

	def __init__(self, file):
		self.buffer = FastIO(file)
		self.flush = self.buffer.flush
		self.writable = self.buffer.writable
		self.write = lambda s: self.buffer.write(s.encode('ascii'))
		self.read = lambda : self.buffer.read().decode('ascii')
		self.readline = lambda : self.buffer.readline().decode('ascii')
(sys.stdin, sys.stdout) = (IOWrapper(sys.stdin), IOWrapper(sys.stdout))
input = lambda : sys.stdin.readline().rstrip('\r\n')
main()


import math
import random
import heapq, bisect
import sys
from collections import deque, defaultdict
from fractions import Fraction
import sys
import threading
from collections import defaultdict
threading.stack_size(10 ** 8)
mod = 10 ** 9 + 7
mod1 = 998244353
import os
import sys
from io import BytesIO, IOBase
sys.setrecursionlimit(300000)
BUFSIZE = 8192

class FastIO(IOBase):
	newlines = 0

	def __init__(self, file):
		self._fd = file.fileno()
		self.buffer = BytesIO()
		self.writable = 'x' in file.mode or 'r' not in file.mode
		self.write = self.buffer.write if self.writable else None

	def read(self):
		while True:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			if not b:
				break
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines = 0
		return self.buffer.read()

	def readline(self):
		while self.newlines == 0:
			b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
			self.newlines = b.count(b'\n') + (not b)
			ptr = self.buffer.tell()
			(self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr))
		self.newlines -= 1
		return self.buffer.readline()

	def flush(self):
		if self.writable:
			os.write(self._fd, self.buffer.getvalue())
			(self.buffer.truncate(0), self.buffer.seek(0))

class IOWrapper(IOBase):

	def __init__(self, file):
		self.buffer = FastIO(file)
		self.flush = self.buffer.flush
		self.writable = self.buffer.writable
		self.write = lambda s: self.buffer.write(s.encode('ascii'))
		self.read = lambda : self.buffer.read().decode('ascii')
		self.readline = lambda : self.buffer.readline().decode('ascii')
(sys.stdin, sys.stdout) = (IOWrapper(sys.stdin), IOWrapper(sys.stdout))
input = lambda : sys.stdin.readline().rstrip('\r\n')

class TreeNode:

	def __init__(self, k, v):
		self.key = k
		self.value = v
		self.left = None
		self.right = None
		self.parent = None
		self.height = 1
		self.num_left = 1
		self.num_total = 1

class AvlTree:

	def __init__(self):
		self._tree = None

	def add(self, k, v):
		if not self._tree:
			self._tree = TreeNode(k, v)
			return
		node = self._add(k, v)
		if node:
			self._rebalance(node)

	def _add(self, k, v):
		node = self._tree
		while node:
			if k < node.key:
				if node.left:
					node = node.left
				else:
					node.left = TreeNode(k, v)
					node.left.parent = node
					return node.left
			elif node.key < k:
				if node.right:
					node = node.right
				else:
					node.right = TreeNode(k, v)
					node.right.parent = node
					return node.right
			else:
				node.value = v
				return

	@staticmethod
	def get_height(x):
		return x.height if x else 0

	@staticmethod
	def get_num_total(x):
		return x.num_total if x else 0

	def _rebalance(self, node):
		n = node
		while n:
			lh = self.get_height(n.left)
			rh = self.get_height(n.right)
			n.height = max(lh, rh) + 1
			balance_factor = lh - rh
			n.num_total = 1 + self.get_num_total(n.left) + self.get_num_total(n.right)
			n.num_left = 1 + self.get_num_total(n.left)
			if balance_factor > 1:
				if self.get_height(n.left.left) < self.get_height(n.left.right):
					self._rotate_left(n.left)
				self._rotate_right(n)
			elif balance_factor < -1:
				if self.get_height(n.right.right) < self.get_height(n.right.left):
					self._rotate_right(n.right)
				self._rotate_left(n)
			else:
				n = n.parent

	def _remove_one(self, node):
		replacement = node.left or node.right
		if node.parent:
			if AvlTree._is_left(node):
				node.parent.left = replacement
			else:
				node.parent.right = replacement
			replacement.parent = node.parent
			node.parent = None
		else:
			self._tree = replacement
			replacement.parent = None
		node.left = None
		node.right = None
		node.parent = None
		self._rebalance(replacement)

	def _remove_leaf(self, node):
		if node.parent:
			if AvlTree._is_left(node):
				node.parent.left = None
			else:
				node.parent.right = None
			self._rebalance(node.parent)
		else:
			self._tree = None
		node.parent = None
		node.left = None
		node.right = None

	def remove(self, k):
		node = self._get_node(k)
		if not node:
			return
		if AvlTree._is_leaf(node):
			self._remove_leaf(node)
			return
		if node.left and node.right:
			nxt = AvlTree._get_next(node)
			node.key = nxt.key
			node.value = nxt.value
			if self._is_leaf(nxt):
				self._remove_leaf(nxt)
			else:
				self._remove_one(nxt)
			self._rebalance(node)
		else:
			self._remove_one(node)

	def get(self, k):
		node = self._get_node(k)
		return node.value if node else -1

	def _get_node(self, k):
		if not self._tree:
			return None
		node = self._tree
		while node:
			if k < node.key:
				node = node.left
			elif node.key < k:
				node = node.right
			else:
				return node
		return None

	def get_at(self, pos):
		x = pos + 1
		node = self._tree
		while node:
			if x < node.num_left:
				node = node.left
			elif node.num_left < x:
				x -= node.num_left
				node = node.right
			else:
				return (node.key, node.value)
		raise IndexError('Out of ranges')

	@staticmethod
	def _is_left(node):
		return node.parent.left and node.parent.left == node

	@staticmethod
	def _is_leaf(node):
		return node.left is None and node.right is None

	def _rotate_right(self, node):
		if not node.parent:
			self._tree = node.left
			node.left.parent = None
		elif AvlTree._is_left(node):
			node.parent.left = node.left
			node.left.parent = node.parent
		else:
			node.parent.right = node.left
			node.left.parent = node.parent
		bk = node.left.right
		node.left.right = node
		node.parent = node.left
		node.left = bk
		if bk:
			bk.parent = node
		node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1
		node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right)
		node.num_left = 1 + self.get_num_total(node.left)

	def _rotate_left(self, node):
		if not node.parent:
			self._tree = node.right
			node.right.parent = None
		elif AvlTree._is_left(node):
			node.parent.left = node.right
			node.right.parent = node.parent
		else:
			node.parent.right = node.right
			node.right.parent = node.parent
		bk = node.right.left
		node.right.left = node
		node.parent = node.right
		node.right = bk
		if bk:
			bk.parent = node
		node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1
		node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right)
		node.num_left = 1 + self.get_num_total(node.left)

	@staticmethod
	def _get_next(node):
		if not node.right:
			return node.parent
		n = node.right
		while n.left:
			n = n.left
		return n

class SegmentTree1:

	def __init__(self, data, default=2 ** 51, func=lambda a, b: a & b):
		self._default = default
		self._func = func
		self._len = len(data)
		self._size = _size = 1 << (self._len - 1).bit_length()
		self.data = [default] * (2 * _size)
		self.data[_size:_size + self._len] = data
		for i in reversed(range(_size)):
			self.data[i] = func(self.data[i + i], self.data[i + i + 1])

	def __delitem__(self, idx):
		self[idx] = self._default

	def __getitem__(self, idx):
		return self.data[idx + self._size]

	def __setitem__(self, idx, value):
		idx += self._size
		self.data[idx] = value
		idx >>= 1
		while idx:
			self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
			idx >>= 1

	def __len__(self):
		return self._len

	def query(self, start, stop):
		if start == stop:
			return self.__getitem__(start)
		stop += 1
		start += self._size
		stop += self._size
		res = self._default
		while start < stop:
			if start & 1:
				res = self._func(res, self.data[start])
				start += 1
			if stop & 1:
				stop -= 1
				res = self._func(res, self.data[stop])
			start >>= 1
			stop >>= 1
		return res

	def __repr__(self):
		return 'SegmentTree({0})'.format(self.data)

class SegmentTree:

	def __init__(self, data, default=0, func=lambda a, b: a + b):
		self._default = default
		self._func = func
		self._len = len(data)
		self._size = _size = 1 << (self._len - 1).bit_length()
		self.data = [default] * (2 * _size)
		self.data[_size:_size + self._len] = data
		for i in reversed(range(_size)):
			self.data[i] = func(self.data[i + i], self.data[i + i + 1])

	def __delitem__(self, idx):
		self[idx] = self._default

	def __getitem__(self, idx):
		return self.data[idx + self._size]

	def __setitem__(self, idx, value):
		idx += self._size
		self.data[idx] = value
		idx >>= 1
		while idx:
			self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1])
			idx >>= 1

	def __len__(self):
		return self._len

	def query(self, start, stop):
		if start == stop:
			return self.__getitem__(start)
		stop += 1
		start += self._size
		stop += self._size
		res = self._default
		while start < stop:
			if start & 1:
				res = self._func(res, self.data[start])
				start += 1
			if stop & 1:
				stop -= 1
				res = self._func(res, self.data[stop])
			start >>= 1
			stop >>= 1
		return res

	def __repr__(self):
		return 'SegmentTree({0})'.format(self.data)

class Factorial:

	def __init__(self, MOD):
		self.MOD = MOD
		self.factorials = [1, 1]
		self.invModulos = [0, 1]
		self.invFactorial_ = [1, 1]

	def calc(self, n):
		if n <= -1:
			print('Invalid argument to calculate n!')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		if n < len(self.factorials):
			return self.factorials[n]
		nextArr = [0] * (n + 1 - len(self.factorials))
		initialI = len(self.factorials)
		prev = self.factorials[-1]
		m = self.MOD
		for i in range(initialI, n + 1):
			prev = nextArr[i - initialI] = prev * i % m
		self.factorials += nextArr
		return self.factorials[n]

	def inv(self, n):
		if n <= -1:
			print('Invalid argument to calculate n^(-1)')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		p = self.MOD
		pi = n % p
		if pi < len(self.invModulos):
			return self.invModulos[pi]
		nextArr = [0] * (n + 1 - len(self.invModulos))
		initialI = len(self.invModulos)
		for i in range(initialI, min(p, n + 1)):
			next = -self.invModulos[p % i] * (p // i) % p
			self.invModulos.append(next)
		return self.invModulos[pi]

	def invFactorial(self, n):
		if n <= -1:
			print('Invalid argument to calculate (n^(-1))!')
			print('n must be non-negative value. But the argument was ' + str(n))
			exit()
		if n < len(self.invFactorial_):
			return self.invFactorial_[n]
		self.inv(n)
		nextArr = [0] * (n + 1 - len(self.invFactorial_))
		initialI = len(self.invFactorial_)
		prev = self.invFactorial_[-1]
		p = self.MOD
		for i in range(initialI, n + 1):
			prev = nextArr[i - initialI] = prev * self.invModulos[i % p] % p
		self.invFactorial_ += nextArr
		return self.invFactorial_[n]

class Combination:

	def __init__(self, MOD):
		self.MOD = MOD
		self.factorial = Factorial(MOD)

	def ncr(self, n, k):
		if k < 0 or n < k:
			return 0
		k = min(k, n - k)
		f = self.factorial
		return f.calc(n) * f.invFactorial(max(n - k, k)) * f.invFactorial(min(k, n - k)) % self.MOD

def powm(a, n, m):
	if a == 1 or n == 0:
		return 1
	if n % 2 == 0:
		s = powm(a, n // 2, m)
		return s * s % m
	else:
		return a * powm(a, n - 1, m) % m

def sort_list(list1, list2):
	zipped_pairs = zip(list2, list1)
	z = [x for (_, x) in sorted(zipped_pairs)]
	return z

def product(l):
	por = 1
	for i in range(len(l)):
		por *= l[i]
	return por

def binarySearchCount(arr, n, key):
	left = 0
	right = n - 1
	count = 0
	while left <= right:
		mid = int((right + left) / 2)
		if arr[mid] < key:
			count = mid + 1
			left = mid + 1
		else:
			right = mid - 1
	return count

def countdig(n):
	c = 0
	while n > 0:
		n //= 10
		c += 1
	return c

def binary(x, length):
	y = bin(x)[2:]
	return y if len(y) >= length else '0' * (length - len(y)) + y

def countGreater(arr, n, k):
	l = 0
	r = n - 1
	leftGreater = n
	while l <= r:
		m = int(l + (r - l) / 2)
		if arr[m] >= k:
			leftGreater = m
			r = m - 1
		else:
			l = m + 1
	return n - leftGreater
(n, k) = map(int, input().split())
l = list(map(int, input().split()))
s = [0] * (n + 1)
for i in range(1, n + 1):
	s[i] = s[i - 1] + l[i - 1]

def check(x):
	dp = [[0 for i in range(k + 1)] for j in range(n + 1)]
	dp[0][0] = 1
	for i in range(1, n + 1):
		for j in range(1, min(i, k) + 1):
			for h in range(i - 1, -1, -1):
				cur = s[i] - s[h]
				if cur & x == x:
					dp[i][j] = max(dp[i][j], dp[h][j - 1])
	return dp[n][k]
temp = 0
cou = 2 ** 57
for i in range(57, -1, -1):
	temp ^= cou
	if check(temp) == 1:
		ans = temp
	else:
		temp ^= cou
		ans = temp
	cou //= 2
print(ans)


[n, k] = map(int, input().strip().split())
ais = list(map(int, input().strip().split()))
iais = [0 for _ in range(n + 1)]
for i in range(n):
	iais[i + 1] = iais[i] + ais[i]

def calc(k, split):
	res = 0
	for i in range(k):
		res &= iais[split[i + 1]] - iais[split[i]]
	return res

def check_mask(mask):
	dp = [[False for j in range(n + 1)] for i in range(k + 1)]
	for j in range(1, n - k + 1 + 1):
		dp[1][j] = iais[j] & mask == mask
	if not any(dp[1]):
		return False
	for i in range(2, k + 1):
		for j in range(i, n - (k - i) + 1):
			dp[i][j] = any((dp[i - 1][r] and iais[j] - iais[r] & mask == mask for r in range(i - 1, j - 1 + 1)))
		if not any(dp[i]):
			return False
	return dp[k][n]
mask = 0
for i in range(55, -1, -1):
	if check_mask(mask | 1 << i):
		mask |= 1 << i
print(mask)