#include <bits/stdc++.h>
#define endl '\n'
#define ll long long
using namespace std;
const ll maxn = (ll)1e5 + 1;
vector<ll> numbers(maxn);
vector<ll> tree(4*maxn);
bool flip;
ll n, m, a, p, b;

void build(int pos, int i, int j){
    int esq = 2*pos;
    int dir = 2*pos + 1;
    int mid = (i+j)/2;

    if(i == j){
        tree[pos] = numbers[i];
    }else{
        tree[pos] = 0;
        build(esq, i, mid);
        build(dir, mid+1,j);
        if(!flip) tree[pos] = tree(esq) | tree(dir);
        else tree[pos] = tree(esq) ^ tree(dir);
        flip = !flip;

    }

}

int update(int pos,int i, int j, int x, int value){
    int esq = 2*pos;
    int dir = 2*pos + 1;
    int mid = (i+j)/2;
    if(i == j){
        tree[pos] = value;
    }else{
        if(!flip){
        if(x <= mid) tree[pos] = update(esq, i, mid, x, value) | tree[dir];
        else tree[pos] = tree[esq] | update(dir, mid+i, j, x, value);
        }
        else{
            if(x <= mid) tree[pos] = update(esq, i, mid, x, value) ^ tree[dir];
            else tree[pos] = tree[esq] ^ update(dir, mid+i, j, x, value);
        }
        flip = !flip;
    }
    return tree[pos];
}
int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
}