//#include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll k;
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >>k;
    vector<vector<vector<string>>> v(10,vector<vector<string>>(10));
    int count=0;
    v[0][0].push_back("0");
    rep(i,10){
        if(i==0)continue;
        string temp=to_string(i);
        count++;
        if(count==k){
            cout<<i<<"\n";
            return 0;
        }
        v[0][i].push_back(temp);
    }
    for(int i=1;i<10;i++){
        for(int j=0;j<10;j++){
            if(j==0){
                rep(h,v[i-1][0].size()){
                    string temp=v[i-1][0][h]+'0';
                    v[i][j].push_back(temp);
                }
                rep(h, v[i - 1][1].size())
                {
                    string temp = v[i - 1][1][h] + '0';
                    v[i][j].push_back(temp);
                }
            }
            else if(j==9){
                rep(h, v[i - 1][8].size())
                {
                    string temp = v[i - 1][8][h] + '9';
                    count++;
                    if(count==k){
                        reverse(ALL(temp));
                        cout<<temp<<"\n";
                        return 0;
                    }
                    v[i][j].push_back(temp);
                    
                }
                rep(h, v[i - 1][9].size())
                {
                    string temp = v[i - 1][9][h] + '9';
                    count++;
                    if (count == k)
                    {
                        reverse(ALL(temp));
                        cout << temp << "\n";
                        return 0;
                    }
                    v[i][j].push_back(temp);
                }
            }
            else{
                rep(h, v[i - 1][j-1].size())
                {
                    string temp = v[i - 1][j-1][h] + to_string(j);
                    count++;
                    if (count == k)
                    {
                        reverse(ALL(temp));
                        cout << temp << "\n";
                        return 0;
                    }
                    v[i][j].push_back(temp);
                }
                rep(h, v[i - 1][j].size())
                {
                    string temp = v[i - 1][j][h] + to_string(j);
                    count++;
                    if (count == k)
                    {
                        reverse(ALL(temp));
                        cout << temp << "\n";
                        return 0;
                    }
                    v[i][j].push_back(temp);
                }
                rep(h, v[i - 1][j+1].size())
                {
                    string temp = v[i - 1][j + 1][h] + to_string(j);
                    count++;
                    if (count == k)
                    {
                        reverse(ALL(temp));
                        cout << temp << "\n";
                        return 0;
                    }
                    v[i][j].push_back(temp);
                }
            }
        }
    }
}


Measured memory_bytes: 6528