#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;
using ll = long long;
int main() {
  ll s, n;
  cin >> n >> s;
  vector<ll> ans;
  for(ll i = n; i >= 1; i--) {
    if(s - i >= 0) {
      ans.push_back(i);
      s -= i;
    }
  }
  reverse(ans.begin(), ans.end());
  cout << ans.size() << endl;
  for(int i = 0; i < ans.size(); i++) {
    cout << ans[i] << " ";
  }
  cout << endl;
  return 0;
}