#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  int n;
  unsigned int a[200];
  unsigned int ans;
  scanf("%d", &n);
  ans = 0;
  for (int i = 0; i < n; i++) scanf("%u", &a[i]);
  for (int i = 0; i < n; i++) {
    unsigned int temp = a[i];
    if (temp > ans) ans = temp;
    for (int j = i + 1; j < n; j++) {
      temp = temp ^ a[j];
      if (temp > ans) ans = temp;
    }
  }
  printf("%u\n", ans);
  return 0;
}
