#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <cstring>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i,n) for (int i = 0; i < int(n);i++)

int main(){
  int n;
  cin >> n;
  n--;
  int x = n/36;
  int y = n%36;
  string ans;
  int a = 0;
  int b = 0;
  int cnt = 0;
  for (int i = 1; i <= 9;i++){
    for (int j = 1; j <= 9;j++){
      if (i >= j) continue;
      if (cnt == y){
        ans = to_string(10*i+j);
        a = i;
        b = j;
      }
      //cout << 10*i+j << endl;
      cnt++;
    }
  }
  for (int i = 0; i < x;i++){
    ans += to_string(b);
  }
  cout << ans << endl;
  

  return 0;
}