#include <bits/stdc++.h>
#define int long long
using namespace std;

signed main(){
  int N,K;
  cin>>N>>K;
  std::vector<int> v(N);
  for(int i=0;i<N;i++)cin>>v[i];
  std::vector<int> w(N+1);
  w[0]=0;
  for(int i=0;i<N;i++)w[i+1]=w[i]+v[i];

  std::vector<int> p[2];
  for(int i=0;i<N;i++)for(int j=i+1;j<N+1;j++)p[0].push_back(w[j]-w[i]);

  int Q=pow(2,40);
  int ans=0;
  int c=0;
  while(Q){
    c=0;
    for(auto x:p[0]){
      if(x&Q){c++;p[1].push_back(x);}
    }
    if(c>=K){
      ans+=Q;
      p[0]=p[1];
    }
    p[1].clear();
    Q/=2;
  }
  cout<<ans<<endl;
}
