#define _CRT_SECURE_NO_WARNINGS #include <iostream> #include <cstdio> #include <cstring> #include <ctime> #include <string> #include <vector> #include <algorithm> #include <cmath> #include <sstream> #include <utility> using namespace std; typedef long long ll; typedef vector<ll> vi; typedef vector<vi> vvi; typedef pair<int,int> pii; #define all(c) (c).begin(), (c).end() #define loop(i,a,b) for(ll i=a; i<ll(b); i++) #define rep(i,b) loop(i,0,b) #define each(e,c) for(auto&e:c) #define pb push_back #define eb emplace_back #define mp make_pair #define mt make_tuple #define lb lower_bound #define ub upper_bound #ifdef DEBUG #define dump(...) (cerr<<#__VA_ARGS__<<" = "<<(DUMP(),__VA_ARGS__).str()<<" ["<<__LINE__<<"]"<<endl) struct DUMP:ostringstream{template<class T>DUMP &operator,(const T&t){if(this->tellp())*this<<", ";*this<<t;return *this;}}; #else #define dump(...) #endif template<class T> ostream& operator<<(ostream& os, vector<T> const& v){ rep(i,v.size()) os << v[i] << (i+1==v.size()?"":" "); return os; } ll mod = 1000000000; ll N,M; int main(){ int N; while(cin>>N && N){ vi a(N); rep(i,N) cin >> a[i]; int x = 0; rep(i,N) x|=a[i]; rep(i,N) a[i]^=x; cout << *max_element(all(a)) << endl; } }