#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <array>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <sstream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <list>
#include <numeric>
#include <stack>
#include <iomanip>
#include <random>
#include <complex>
#include <functional>
#include <tuple>

using namespace std;

#define Rep(i,a,b) for(ll i = a; i < b; ++i)
#define rep(i,b) Rep(i,0,b)
#define allof(a) (a).begin(), (a).end()

#define Yes(q) ((q) ? "Yes" : "No")
#define YES(q) ((q) ? "YES" : "NO")
#define Possible(q) ((q) ? "Possible" : "Impossible")
#define POSSIBLE(q) ((q) ? "POSSIBLE" : "IMPOSSIBLE")

using ll = long long;

using pint = std::pair<int, int>;
using pll = std::pair<ll, ll>;


constexpr int inf = 1e9 + 7;
constexpr ll infll = 1ll << 60ll;
constexpr ll mod = 1e9 + 7;
// 0~3までは右左下上 4~7までは斜め
constexpr int dx[] = { 1, 0, -1, 0, 1, 1, -1, -1 };
constexpr int dy[] = { 0, -1, 0, 1, 1, -1, -1, 1 };

namespace {
    template<typename T> void chmax(T& a, T b) { a = std::max(a, b); }
    template<typename T> void chmin(T& a, T b) { a = std::min(a, b); }
    template<typename T> void chadd(T& a, T b) { a = a + b; }

    void Cout(long long x, const char* end = "\n") { std::cout << x << end; }
    template <typename T> void Cout(const T& x, const char* end = "\n") { std::cout << x << end; }
    template <typename T> void Cout(const std::vector<T>& x, const char* sep = " ", const char* end = "\n") { for (std::size_t i = 0, sz = x.size(); i < sz; i++) { std::cout << x[i] << (i == sz - 1 ? end : sep); } }

    void CCout(long long x, const char* end = "\n") { std::cerr << x << end; }
    template <typename T> void CCout(const T& x, const char* end = "\n") { std::cerr << x << end; }
    template <typename T> void CCout(const std::vector<T>& x, const char* sep = " ", const char* end = "\n") { for (std::size_t i = 0, sz = x.size(); i < sz; i++) { std::cerr << x[i] << (i == sz - 1 ? end : sep); } }

    // 標準入出力
    struct inp {
        std::size_t sz;
        inp(std::size_t _sz = 1) : sz(_sz) {}
        template <typename T> operator T () const { T a; std::cin >> a; return a; }
        template <typename T> operator std::vector<T>() const { vector<T> a(sz); for (std::size_t i = 0; i < sz; i++) std::cin >> a[i]; return a; }
        template <typename T, typename U> operator std::pair<T, U>() const { T f; U s; std::cin >> f >> s; return std::pair<T, U>(f, s); }
    };

    inp inp1; // input one
}

int main() {

    int k = inp1;

    queue<ll> que;

    int cnt = 0;
    Rep(i, 1, 10) {
        ++cnt;
        if (cnt == k) {
            Cout(i);
            return 0;
        }
        que.push(i);
    }

    ll ans = 0;

    while (cnt != k) {
        ll val = que.front(); que.pop();

        val *= 10;
        // 下から二桁目を見る
        int d = (val % 100) / 10;
        for (int i = -1; i <= 1; ++i) {
            if (d + i >= 0 && d + i <= 9) {
                ll tmp = val + d + i;
                ++cnt;
                if (cnt == k) {
                    ans = tmp;
                    break;
                }
                que.push(tmp);
            }
        }
    }

    Cout(ans);

    return 0;
}


Measured memory_bytes: 768