#include <cstdio>
#include <iostream>
#include <bitset>
#include <algorithm>const int BUF = 12312323;
char Buf[BUF], *buf = Buf;inline void read (int &now)
{for (now = 0; !isdigit (*buf); ++ buf);for (; isdigit (*buf); now = now * 10 + *buf - '0', ++ buf);
}#define Max 300002
#define _L 31struct Bit { int a; bool c[_L]; };
inline bool Comp (Bit A, Bit B) { return A.a > B.a; }
Bit key[Max];
int max (int a, int b) { return a > b ? a : b; }int Main ()
{freopen ("and.in", "r", stdin);freopen ("and.out", "w", stdout);fread (buf, 1, BUF, stdin);int N, x; read (N); register int i, j, k;for (i = 1; i <= N; ++ i){read (x), j = 31; key[i].a = x;for (; x; x >>= 1) key[i].c[-- j] = x % 2;    }std :: sort (key + 1, key + 1 + N, Comp);long long Answer = 0;if (key[1].a == key[2].a) return printf ("%d", key[1].a), 0;int pos; static int mi[10]; mi[1] = 2;for (i = 2; i <= 31; ++ i)mi[i] = mi[i - 1] * 2;Answer = key[1].a & key[2].a;for (j = 0; j < _L; ++ j){pos = 0;for (i = 1; i <= N; ++ i){if (key[i].c[j] == 0 && i > pos) { pos = i; break; }if (key[i].a == key[i - 1].a)Answer = max (Answer, key[i].a);}for (i = 1; i < pos; i ++)key[i].a -= mi[_L - j]; }printf ("%d", Answer);return 0;
}int ZlycerQan = Main ();
int main (int argc, char *argv[]) {;}

#include <cstdio>
#include <iostream>
#include <cstring>const int BUF = 12312312;
char Buf[BUF], *buf = Buf;
#define Max 55
inline void read (int &now)
{for (now = 0; !isdigit (*buf); ++ buf);for (; isdigit (*buf); now = now * 10 + *buf - '0', ++ buf);
}
typedef double flo;
int c[Max];
flo f[Max][Max << 1], s[Max], Answer;int Main ()
{freopen ("elephant.in", "r", stdin);freopen ("elephant.out", "w", stdout);fread (buf, 1, BUF, stdin);int T; read (T); int N, C, K, x, y;for (register int i, j, k; T; -- T){read (N), read (C), read (K);memset (f, 0, sizeof f); memset (s, 0, sizeof s);memset (c, 0, sizeof c); Answer = 0; f[0][1] = 1;for (i = 1; i <= K; ++ i){read (x), read (y);for (j = x; j <= y; ++ j) ++ c[j];}for (i = 0; i <= K; ++ i)for (j = 0; j < C; ++ j){f[i + 1][j] += f[i][j] * 0.5;for (k = 0; k < C; ++ k)f[i + 1][j * k % C] += f[i][j] * 0.5 / C;}for (i = 0; i <= K; ++ i)for (j = 0; j < C; ++ j)s[i] += f[i][j] * j;for (i = 1; i <= N; ++ i) Answer += s[c[i]];printf ("%.9lf\n", Answer);}    return 0;
}
int ZlycerQan = Main ();
int main (int argc, char *argv[]) {;}

#include <cstdio>
#include <iostream>
#include <queue>
#include <cstring>const int BUF = 12312313;
char Buf[BUF], *buf = Buf;
#define INF (1 << 30)
inline void read (int &now)
{for (now = 0; !isdigit (*buf); ++ buf);for (; isdigit (*buf); now = now * 10 + *buf - '0', ++ buf);
}#define P_Q std :: priority_queue <D>
inline int min (int a, int b) { return a < b ? a : b; }struct D
{int id, c, d; D () {}D (int _x, int _y, int _z) : id (_x), c (_y), d (_z) {}bool operator < (const D now) const{return this->d > now.d;}
};#define Max 10009
struct E { int v, d; E *n; };
E poor[Max * 50], *list[Max], *Ta = poor;
P_Q Heap;
bool visit[Max][12];
int f[Max][12];int Main ()
{freopen ("move.in", "r", stdin);freopen ("move.out", "w", stdout);fread (buf, 1, BUF, stdin);int N, M, K, S, T; read (N), read (M), read (K);register int i, j; int x, y, z; read (S), read (T);for (i = 1; i <= M; ++ i){read (x), read (y), read (z);++ Ta, Ta->v = y, Ta->d = z, Ta->n = list[x], list[x] = Ta;++ Ta, Ta->v = x, Ta->d = z, Ta->n = list[y], list[y] = Ta;}Heap.push (D (S, 0, 0)); D res; int V, C, now;memset (f, 0x3f, sizeof f); E *e; int Answer = INF;for (f[S][0] = 0; !Heap.empty (); Heap.pop ()){res = Heap.top (); now = res.id, C = res.c;if (visit[now][C]) continue;visit[now][C] = true;for (e = list[now]; e; e = e->n){V = e->v;if (f[V][C] > f[now][C] + e->d){f[V][C] = f[now][C] + e->d;Heap.push (D (V, C, f[V][C]));    }if (C < K && f[V][C + 1] > f[now][C]){f[V][C + 1] = f[now][C];Heap.push (D (V, C + 1, f[V][C + 1]));}}}for (i = 0; i <= K; ++ i) Answer = min (Answer, f[T][i]);printf ("%d", Answer);    return 0;
}
int ZlycerQan = Main ();
int main (int argc, char *argv[]) { ; }