#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<n; i++)
#define Sort(vector) sort(vector.begin(), vector.end())
#define Reverse(vector) reverse(vector.begin(), vector.end())
#define RSort(vector) sort(vector.rbegin(), vector.rend())
using ll = long long;
using P = pair<int,int>;
using TU = tuple<char,char,int>;
using vint = vector<int>;
using vvint = vector<vint>;
using vvvint = vector<vvint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
template<typename T> istream &operator>>(istream &is,vector<T> &v){for(T &in:v){is>>in;}return is;}
template<typename T> ostream &operator<<(ostream &os,vector<T> &v){for(int i=0;i<(int)v.size();i++){os<<v[i]<<" \n"[i==(int)v.size()-1];}return os;}
template<typename T> istream &operator>>(istream &is,vector<vector<T>> &v){for(vector<T> &in:v){is>>in;}return is;}
template<typename T> ostream &operator<<(ostream &os,vector<vector<T>> &v){for(vector<T> &out:v){os<<out;}return os;}




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

  queue<TU> q;
  for(int a=1;a<=9;a++){
    for(int b=a+1;b<=9;b++){
      q.push({'0'+a,'0'+b,1});
    }
  }

  TU res;
  rep(i,n) {
    res=q.front(); q.pop();

    auto [a,b,num]=res;
    q.push({a,b,num+1});
  }

  auto [a,b,num]=res;

  cout<< a;
  rep(i,num) cout<< b;
  cout<<'\n';


  return 0;
}