#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include //#include using namespace std; //using namespace atcoder; #define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++) #define rep(i, n) repr(i, 0, n) #define INF 2e9 //#define MOD 1000000007 #define MOD 998244353 #define LINF (long long)4e18 #define jck 3.141592 #define PI acos(-1.0) const double EPS = 1e-18; using ll = long long; using Pi = pair; using Pl = pair; //using mint = modint998244353; int dh[] = {-1,1,0,0}; int dw[] = {0,0,1,-1}; int main(){ int n; cin >> n; vector a(n); rep(i,n) cin >> a[i]; rep(i,61){ bool ok = all_of(a.begin(),a.end(),[&](auto x){ return !(x>>i&1); }); if(ok){ cout << (1LL<