#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    vector<int> answer = {2,4,6,12,24,48,96,192,128};
    long long lcm = 1,sum = 0;
    for(auto a : answer) lcm = lcm*a/gcd(lcm,a),sum += a;

    cout << answer.size() << endl;
    for(auto a : answer) cout << a << " "; cout << endl;
}