#include <iostream>
#include <queue>
#include <assert.h>   
#include <vector>
#include <algorithm>
#include <time.h>
#include <numeric>
#include <string>
#include <cstring>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#include <set>
#include <map>
#include <numeric>
#include <deque>
#include <iomanip>
#include <cstdlib>
#include <climits>
#include <cmath>
#include <cstdio>
using namespace std;


//#define double long double
#define int long long
//#define int unsigned long long

#define ll long long
#define ld long double 
#define pi pair<int, int> 
#define pl pair<ll,ll>  
#define pd pair<ld,ld> 
#define str string  
#define mp make_pair
#define vi vector<int> 
#define vl vector<ll> 
#define vd vector<ld> 
#define vs vector<str> 
#define vpi vector<pi> 
#define vpl vector<pl> 
#define vpd vector<pd> 
#define si set<int> 
#define FF(i,j,n) for(signed i=j;i<=n;i++)  
#define DD(i,j,n) for(signed i=j;i>=n;i--) 
#define F(i,j,n) for(signed i=j;i<n;i++)   
#define D(i,j,n) for(signed i=j;i>n;i--) 
#define mem(a,b) memset(a,b,sizeof(a))
#define ndl cout << endl
#define ull unsigned long long 

const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3fLL;


#define sz(x) (signed)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back() 
#define fi first
#define se second
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 
#define IOS ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

//math


const int mod = 1e9 + 7;

ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
int pct(int x) { return __builtin_popcount(x); } 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 


//DEBUG, compile with -DLOCAL
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
  cerr << to_string(h); if (sizeof...(t)) cerr << ", ";
  DBG(t...); }
#ifdef LOCAL 
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#define HERE cout << "===GOTHERE===" << endl
#else
#define dbg(...) 42
#define HERE 42
#endif


 /* ============== END OF HEADER ============== */





const int maxn = 1e5*3+20;

int n,_,q,k;

int a[1005];
int val[1005][1005];
int bit = 0;


vi check(vi curr, int b){
	sort(all(curr), [&b](int x, int y){
		return (x & ((ll)1 << b)) > (y & ((ll)1<<b));
	});
	int id;
	for(id = 0; id < sz(curr); id++){
		if(!(curr[id] & ((ll)1 << b))) break;
	}
	if(id >= k){
		bit = 1;
		vi next(curr.begin(), curr.begin() + id);
		return next;
	}else{
		bit = 0;
		return curr;
	}
}



void solve(){
	cin >> n >> k;
	FF(i,1,n){
		cin >> a[i];
		val[i][i] = a[i];
	}
	//compute all the vals
	FF(len,2,n){
		for(int l = 1; l + len - 1 <= n; l++){
			int r = l + len - 1;
			val[l][r] = val[l][r-1] + a[r];
		}
	}
	// FF(i,1,n){
	// 	FF(j,1,n){
	// 		cout << val[i][j] << " ";
	// 	}
	// 	cout << endl;
	// }

	//all possible & vals
	vi nums;
	FF(i,1,n){
		FF(j,1,n){
			if(val[i][j])
				nums.eb(val[i][j]);
		}
	}
	dbg(sz(nums));

	//shift 0-63
	int res = 0;
	DD(i,63,0){
		nums = check(nums, i);
		if(bit) res |= ((ll)1 << i);
	}


	cout << res << endl;

}	

signed main(){
  //clock_t t1 = clock();  
	IOS
	solve();
  
  //cout << "THE ALGORITHM TOOK: " << (clock() - t1) * 1.0 / CLOCKS_PER_SEC * 1000 << "ms"<< endl;
	return 0;
}

Measured memory_bytes: 16220