// 129
#include <bits/stdc++.h>
using namespace std;
vector<int> ans;
int stk[25], tot, n, cnt;
void dfs(int now)
{
    if (cnt >= 20)
        return;
    if (now > n)
    {
        cnt++;
        for (auto x : ans)
            cout << x;
        for (int i = tot - 1; i >= 0; i--)
            cout << stk[i];
        puts("");
        return;
    }
    if (tot)
    {
        ans.push_back(stk[--tot]);
        dfs(now);
        stk[tot++] = ans.back();
        ans.pop_back();
    }
    stk[tot++] = now;
    dfs(now + 1);
    tot--;
}

int main()
{
    cin >> n;
    dfs(1);
    return 0;
}