#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <algorithm>
#include <set>
#include <map>
#include <bitset>
#include <cmath>
#include <functional>
#include <iomanip>
#define vll vector<ll>
#define vvvl vector<vvl>
#define vvl vector<vector<ll>>
#define VV(a, b, c, d) vector<vector<d>>(a, vector<d>(b, c))
#define VVV(a, b, c, d) vector<vvl>(a, vvl(b, vll (c, d)));
#define re(c, b) for(ll c=0;c<b;c++)
#define rep(a,b,c) for(ll a=b;a<c;a++)
#define all(obj) (obj).begin(), (obj).end()
typedef long long int ll;
typedef long double ld;
using namespace std;

void get(vll &a){re(i,a.size()) scanf("%lld",&a[i]);}
void get(vvl &a){re(i,a.size()) re(j,a[0].size()) scanf("%lld",&a[i][j]);}
void print(vll &a){re(i,a.size()) cout<<a[i]<<(i==a.size()-1?"\n":" ");}
void print(vvl &a){re(i,a.size()) re(j,a[0].size())cout<<a[i][j]<<(j==a[0].size()-1?"\n":" ");}

struct segtree{
  ll M=1, INIT;
  vector<ll> dat;
  segtree(ll N, ll num){
    INIT = num;
    while(M<N) M*=2;
    dat.resize(M*2-1, num);
  }
  inline void update(ll x, ll k, ll l=0, int r=-1){
    if(r==-1) r = M;
    k+=M-1;
    dat[k] = x;
    while(k>0) k = (k-1)/2, dat[k] = dat[k*2+1] ^ dat[k*2+2];
  }
  inline ll query(ll a, ll b=-1, ll k=0, ll l=0, ll r=-1){
    if(r==-1) r = M;
    if(b==-1) b = M;
    if(r<=a || b<=l) return INIT;
    if(a<=l && r<=b) return dat[k];
    ll A = query(a, b, k*2+1, l, (l+r)/2);
    ll B = query(a, b, k*2+2, (l+r)/2, r);
    return A ^ B;
  }
};
int main(int argc, char const *argv[]) {
  ll n, q;std::cin >> n >> q;
  vll a(n);get(a);
  segtree seg(n, 0);
  for(int i=0;i<n;i++) seg.update(a[i], i);
  re(i, q){
    ll l, r;scanf("%lld %lld", &l, &r);
    printf("%lld\n", seg.query(l-1, r));
  }
  return 0;
}