#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

int main(){
    int N;
    cin >> N;

    vector<pair<int,int>> cow;
    for(int a = 1; a <= 9; ++a){
        for(int b = a+1; b <= 9; ++b){
            cow.push_back({a, b});
        }
    }

    int n = cow.size();
    int d = N / n, i = N % n;

    cout << cow[i-1].first;
    rep(j, 0, d+1) cout << cow[i-1].second;
    cout << endl;

    return 0;
}