#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) { return (ull)rng() % B; }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    vector<pair<int, int>> v;
    for (int i = 1; i < 10; i++) {
        for (int j = i + 1; j < 10; j++) {
            v.push_back({i * 10 + j, j});
        }
    }
    int m = v.size();
    int n;
    cin >> n;
    n -= 1;
    cout << v[n % m].first;
    for (int i = 0; i < n / m; i++) {
        cout << v[n % m].second;
    }
    cout << endl;
}