#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int n;
  cin >> n;
  --n;
  int c = n / 36;
  int r = n % 36;
  vector<int> cand;
  for (int a = 1; a <= 9; a++) {
    for (int b = a + 1; b <= 9; b++) {
      cand.push_back(10 * a + b);
    }
  }
  cout << cand[r];
  rep(_, c) cout << cand[r] % 10;
  cout << endl;
  return 0;
}