#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;

int main()
{
    int n, x; cin>>n>>x;
    if(x==1){
        if(n%4==0){
            cout<<1<<endl;
            cout<<2<<endl;
            cout<<4<<endl;
            cout<<6<<endl;
            for(int i=0; i<n-4; i++) cout<<i+8<<endl;
        }else if(n%4==1){
            for(int i=0; i<n; i++) cout<<i+1<<endl;
        }else if(n%4==2){
            for(int i=0; i<n; i++) cout<<i+2<<endl;
        }else{
            cout<<3<<endl;
            cout<<4<<endl;
            cout<<6<<endl;
            for(int i=0; i<n-3; i++) cout<<i+8<<endl;
        }
    }else{
        if(n%4==0){
            cout<<x<<endl;
            cout<<1<<endl;
            int c=0, i=0;
            for(; c<n-2; i++){
                if(2*i+2==x || 2*i+3==x) continue;
                cout<<2*i+2<<endl;
                cout<<2*i+3<<endl;
                c+=2;
            }
        }else if(n%4==1){
            cout<<x<<endl;
            int c=0, i=0;
            for(; c<n-1; i++){
                if(2*i+2==x || 2*i+3==x) continue;
                cout<<2*i+2<<endl;
                cout<<2*i+3<<endl;
                c+=2;
            }
        }else if(n%4==2){
            cout<<(x^1)<<endl;
            cout<<1<<endl;
            int c=0, i=0;
            for(; c<n-2; i++){
                if(2*i+2==x || 2*i+3==x) continue;
                cout<<2*i+2<<endl;
                cout<<2*i+3<<endl;
                c+=2;
            }
        }else{
            cout<<(x^1)<<endl;
            int c=0, i=0;
            for(; c<n-1; i++){
                if(2*i+2==(x^1) || 2*i+3==(x^1)) continue;
                cout<<2*i+2<<endl;
                cout<<2*i+3<<endl;
                c+=2;
            }
        }
    }
    return 0;
}