#include <algorithm>
#include <cstdint>
#include <functional>
#include <iostream>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;
#define REP(i, n) for (int i = 0; i < n; i++)
#define FOR(i, s, t) for (int i = s; i < t; i++)
#define ALL(obj) obj.begin(), obj.end()

const int iINF = 1e9;
const long long llINF = 1e18;
const int MOD = 1e9 + 7;
template <class T>
inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return 1;
    }
    return 0;
}

template <std::uint_fast64_t Modulus>
class ModInt {
    using u64 = std::uint_fast64_t;

   public:
    u64 a;

    constexpr ModInt(const u64 x = 0) noexcept : a(x % Modulus) {}
    constexpr u64 &value() noexcept { return a; }
    constexpr const u64 &value() const noexcept { return a; }
    constexpr ModInt operator+(const ModInt rhs) const noexcept { return ModInt(*this) += rhs; }
    constexpr ModInt operator-(const ModInt rhs) const noexcept { return ModInt(*this) -= rhs; }
    constexpr ModInt operator*(const ModInt rhs) const noexcept { return ModInt(*this) *= rhs; }
    constexpr ModInt operator/(const ModInt rhs) const noexcept { return ModInt(*this) /= rhs; }
    constexpr ModInt &operator+=(const ModInt rhs) noexcept {
        a += rhs.a;
        if (a >= Modulus) {
            a -= Modulus;
        }
        return *this;
    }
    constexpr ModInt &operator-=(const ModInt rhs) noexcept {
        if (a < rhs.a) {
            a += Modulus;
        }
        a -= rhs.a;
        return *this;
    }
    constexpr ModInt &operator*=(const ModInt rhs) noexcept {
        a = a * rhs.a % Modulus;
        return *this;
    }
    constexpr ModInt &operator/=(ModInt rhs) noexcept {
        u64 exp = Modulus - 2;
        while (exp) {
            if (exp % 2) {
                *this *= rhs;
            }
            rhs *= rhs;
            exp /= 2;
        }
        return *this;
    }
};

using mint = ModInt<MOD>;

long long modPow(long long x, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * x % mod;
        x = x * x % mod;
        n >>= 1;
    }
    return res;
}

long long extGCD(long long a, long long b, long long &x, long long &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }

    long long d = extGCD(b, a % b, y, x);
    y -= a / b * x;
    return d;
}

long long gcd(long long a, long long b) {
    if (b == 0) {
        return a;
    } else {
        return gcd(b, a % b);
    }
}

long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }

template <typename T>
using Vec = vector<T>;
template <typename T>
using VVec = vector<vector<T>>;
using i64 = long long;
int main() {
    int K;
    cin >> K;
    Vec<i64> v;
    FOR(i, 1, 10) { v.push_back(i); }

    for (int i = 0; v.size() < K + 1; i++) {
        i64 tmp = v[i] % 10;
        if (tmp != 0) {
            v.push_back(v[i] * 10 + tmp - 1);
        }
        v.push_back(v[i] * 10 + tmp);
        if (tmp != 9) {
            v.push_back(v[i] * 10 + tmp + 1);
        }
    }

    cout << v[K - 1] << endl;
    return 0;
}

Measured memory_bytes: 1400