#include <fstream>
using namespace std;

ifstream in("farfurii.in");
ofstream out("farfurii.out");

int n,k,el=1;
int main()
{
    in>>n>>k;

    while(el*(el-1)/2<k) el++;

    out<<el<<'\n';
    for(int i=1; i<=n-el; i++) out<<i<<" ";
    out<<n+k-el*(el-1)/2<<" ";
    for(int i=n; i>n-el; i--)
        if(i!=n+k-el*(el+1)/2) out<<i<<" ";

    return 0;
}