#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<cmath>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<unordered_map>
#define x first
#define y second
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define pii pair<char,int>
// #define int long long
using namespace std;
string pp(int a){
  if(a == 0){
    return "0";
  }
  if(a == 1){
    return "1";
  }
  return "2";
}
string bn(int a){
  if(a < 2){
    return pp(a);
  }else{
    return bn(a / 2) + pp(a % 2);
  }
}
int f(int a,int b){
  string p = bn(a),q = bn(b);
  while(p.size() < q.size()){
    p = "0" + p;
  }
  while(q.size() < p.size()){
    q = "0" + q;
  }
  // cout << p << ' ' << q << endl;
  for(int i = 0;i < p.size();i++){
    if(p[i] > q[i]){
      return (p.size() - i - 1);
    }
    if(p[i] < q[i]){
      break;
    }
  }
  return -1;
}
signed main(){
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n,q;
  cin >> n;
  vector<int>a(n);
  for(int i = 0;i < n;i++){
    cin >> a[i];
  }
  cin >> q;
  int p,x;
  int cnt = 0;
  q++;
  vector<int>ans;
  while(q--){
    if(cnt != 0){
     cin >> p >> x;
    a[p - 1] = x;
    }
    cnt++;
    int b = 0;
    for(int i = 0;i < n - 1;i++){
      int kk = f(a[i] ^ b,a[i + 1] ^ b);
      if(kk != -1){
        b |= (1 << kk);
      }
    }
    // cout << b << endl;
    bool ok = 1;
    for(int i = 0;i < n - 1;i++){
      if((a[i + 1] ^ b) < (a[i] ^ b)){
        ok = 0;
        break;
      }
    }
    if(ok){
      cout << b << endl;
    }else{
      cout << -1 << endl;
    }
  }
  return 0;
}