#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll N, d, r;
    cin >> N;
    vector<pair<int, int>> v;
    for (int i=1; i<=9; i++){
        for (int j=i+1; j<=9; j++) v.push_back({i, j});
    }

    d = (N-1)/36+2;
    r = (N-1)%36;

    cout << v[r].first;
    for (int i=1; i<d; i++) cout << v[r].second;
    cout << endl;

    return 0;
}