#include <bits/stdc++.h>
#define optimization std::ios_base::sync_with_stdio(0); cin.tie(0);
#define _int unsigned long long int

using namespace std;

_int binarySearch(_int arr[], _int x, _int low, _int high) {
    if(low <= high) {
        _int mid = (high + low) / 2;
        if(arr[mid] == x)
            return mid;
        else if(arr[mid] > x)
            binarySearch(arr, x, low, mid - 1);
        else
            binarySearch(arr, x, mid + 1, high);
    }
    else
        return -1;
}

int main(int argc, char *argv[]) {
    optimization
    _int n, k, x;
    cin >> n >> k;
    _int *nums = new _int[n];
    x = (n % 2 == 0 ? n / 2 : (n + 1) / 2);
    for (_int i = 0, l = 0, j = 1; j < n + 1; j++) {
        if (j % 2 == 0) {
            nums[x + i] = j;
            i++;
        }
        else {
            nums[l] = j;
            l++;
        }
    }
    for (_int i = 0; i < n; i++)
        cout << nums[i] << " ";
    cout << "\n";
    if (k )
        cout << binarySearch(nums, k, x, n) << "\n";
    else
        cout << binarySearch(nums, k, 0, x) << "\n";
    return 0;
}