#include <bits/stdc++.h>
using namespace std;
struct InputReader {
  char buf[1048576];
  int p;
  inline InputReader() { p = 1048576; }
  inline void Flush() {
    p = 0;
    fread(buf, 1, 1048576, stdin);
  }
  inline char C() {
    if (p >= 1048576) Flush();
    return buf[p++];
  }
  inline char Readnum() {
    char ch = C();
    while (!isdigit(ch) && ch != '-') ch = C();
    return ch;
  }
  inline void Readalpha(char &c) {
    c = C();
    while (!isalpha(c)) c = C();
  }
  int operator()() {
    int ans = 0, fu = 1;
    char ch = Readnum();
    if (ch == '-') fu = -1, ch = C();
    while (ch >= '0' && ch <= '9') {
      ans = ans * 10 + ch - '0';
      ch = C();
    }
    return ans * fu;
  }
  long long Readll() {
    long long ans = 0LL, fu = 1LL;
    char ch = Readnum();
    if (ch == '-') fu = -1LL, ch = C();
    while (ch >= '0' && ch <= '9') {
      ans = ans * 10LL + ch - '0';
      ch = C();
    }
    return ans * fu;
  }
  inline void Readstring(string &x) {
    x.clear();
    char ch = C();
    while (!isdigit(ch) && !isalpha(ch) && ch != '#' && ch != '.') ch = C();
    while (isdigit(ch) || isalpha(ch) || ch == '#' || ch == '.') {
      x += ch;
      ch = C();
    }
  }
  inline void Readchstring(char s[]) {
    int len = 0;
    char ch = C();
    while (!isdigit(ch) && !isalpha(ch)) ch = C();
    while (isdigit(ch) || isalpha(ch)) {
      s[len++] = ch;
      ch = C();
    }
    s[len] = '\0';
  }
  inline void Specialread(char &c) {
    c = C();
    while (!isdigit(c) && !isalpha(c) && c != '#' && c != '.' && c != '=' &&
           c != 'B')
      c = C();
  }
} In;
inline void Read(int &x) { x = In(); }
inline void Read(int &x, int &y) {
  x = In();
  y = In();
}
inline void Read(int &x1, int &x2, int &x3) {
  x1 = In();
  x2 = In();
  x3 = In();
}
inline void Read(int &x1, int &x2, int &x3, int &x4) {
  x1 = In();
  x2 = In();
  x3 = In();
  x4 = In();
}
inline void Read(long long &x) { x = In.Readll(); }
inline void Read(long long &x, long long &y) {
  x = In.Readll();
  y = In.Readll();
}
inline void Read(long long &x1, long long &x2, long long &x3) {
  x1 = In.Readll();
  x2 = In.Readll();
  x3 = In.Readll();
}
inline void Read(long long &x1, long long &x2, long long &x3, long long &x4) {
  x1 = In.Readll();
  x2 = In.Readll();
  x3 = In.Readll();
  x4 = In.Readll();
}
template <typename T>
void Read(T a[], int st, int ed) {
  for (int(i) = (st); (i) <= (ed); ++(i)) Read(a[i]);
}
inline void FILEIO() {}
inline void FILEIO(string pname) {
  freopen((pname + ".in").c_str(), "r", stdin);
  freopen((pname + ".out").c_str(), "w", stdout);
}
inline void FILEIO_OICONTEST(string pname) {
  freopen((pname + ".in").c_str(), "r", stdin);
  freopen((pname + ".out").c_str(), "w", stdout);
}
void Printtime() {}
void END() {
  Printtime();
  exit(0);
}
template <typename T>
void END(T mes) {
  cout << mes << endl;
  END();
}
template <typename T>
void Print(T a[], int s, int t, char sp = ' ', char ed = '\n') {
  if (s > t) return;
  for (int i = s; i < t; i++) cout << a[i] << sp;
  cout << a[t] << ed;
  cout.flush();
}
template <typename T>
void Print(T a, int s = 0, int t = -1, char sp = ' ', char ed = '\n') {
  if (t == -1) t = a.size() - 1;
  for (int i = s; i <= t; i++) cout << a[i] << sp;
  cout << ed;
  cout.flush();
}
vector<int> Range(int l, int r) {
  vector<int> ret{};
  for (int(i) = (l); (i) <= (r); ++(i)) ret.push_back(i);
  return ret;
}
mt19937 Rand(0xe38195e38293);
const int MAXN = 262144;
struct Node {
  int s[2];
} t[2097152];
int root, nownode;
void Insert(int &pos, int x, int wei) {
  if (!pos) {
    pos = ++nownode;
    t[pos].s[0] = t[pos].s[1] = 0;
  }
  if (wei < 0) return;
  Insert(t[pos].s[x >> wei & 1], x, wei - 1);
}
int XorMin(int pos, int x, int wei) {
  if (wei < 0) return 0;
  bool want = x >> wei & 1;
  if (t[pos].s[want])
    return XorMin(t[pos].s[want], x, wei - 1);
  else
    return XorMin(t[pos].s[want ^ 1], x, wei - 1) | 1 << wei;
}
int n;
long long ans = 0;
void Solve(const vector<int> &a, int wei) {
  if (a.empty()) return;
  if (wei < 0) return;
  vector<int> L{}, R{};
  for (auto x : a) {
    if (x >> wei & 1)
      R.push_back(x);
    else
      L.push_back(x);
  }
  if (!L.empty() and !R.empty()) {
    root = nownode = 0;
    int minx = (0x3f3f3f3f);
    for (auto x : L) Insert(root, x, 30);
    for (auto x : R) {
      int tmin = XorMin(root, x, 30);
      (minx) = min((minx), (tmin));
    }
    ans += minx;
  }
  Solve(L, wei - 1);
  Solve(R, wei - 1);
}
int main() {
  FILEIO();
  Read(n);
  static vector<int> initial;
  for (int(i) = 1; (i) <= (n); ++(i)) {
    int x;
    Read(x);
    ;
    initial.push_back(x);
  }
  Solve(initial, 30);
  cout << ans << endl;
  END();
}
