#include <fstream>
#include <iostream>
#include <vector>

using namespace std;

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

vector<int> solutii;
vector<int> first_one;

vector<bool> col(20,false);
vector<bool> diag1(20,false);
vector<bool> diag2(20,false);

bool checked = false;
int count = 0;
int n;

void search(int y)
{
        if(y == n)
        {
                if(checked == false)
                {
                        first_one = solutii;
                        checked = true;
                }
                count++;
        }
        for(int i = 0; i < n; i++ )
        {
                if(col[i] || diag1[i+y] || diag2[i+n-y-1])
                        continue;
                solutii.push_back(i);
                col[i] = diag1[i+y] = diag2[i+n-y-1] = true;
                search(y+1);
                col[i] = diag1[i+y] = diag2[i+n-y-1] = false;
                solutii.pop_back();
        }
}
int main()
{
        in >> n;
        search(0);
        out << count <<'\n';
        for(auto var : first_one)
                out << var + 1 << ' ';

        return 0;
}