/*
    Ujjawal Pabreja
*/
#include <bits/stdc++.h> 
#include <functional> 
using namespace std;
using ll = long long;
using ld = long double;
#define speed_cubing    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define rep(i,a)        for(ll i = 0 ; i < a ; i++)
#define repe(i,a,b)     for(ll i = a ; i < b ; i++)
#define bac(i,a)        for(ll i = a ; i >= 0 ; i--)
#define bace(i,a,b)     for(ll i = a ; i >= b ; i--)
#define pb              push_back
#define mp              make_pair
#define in              insert
#define ff              first
#define ss              second
#define vv              vector
#define vll             vector <ll>
#define pll             pair <ll,ll>
#define vpll            vector <pll>
#define umap            unordered_map
#define uset            unordered_set
#define mset            multiset
#define pqueue          priority_queue
#define setbit(x)       __builtin_popcountll(x)
#define init(c,a)       memset(c,a,sizeof(c))
#define all(c)          c.begin(),c.end()
#define sz(c)           (ll)c.size()
#define lb              lower_bound
#define ub              upper_bound
#define maxe            *max_element
#define mine            *min_element
#define gcd(a,b)        __gcd(a,b)
#define rev             reverse
#define Y               "YES"
#define N               "NO"
#define nl              "\n"
#define debug(x)        cout << #x << " : " << x << nl;
const ll inf = 1e8;  
const ll mod = 1e9 + 7;
const ll MOD = 998244353;
const ll MAX = 2e5 + 1;

// ====== int_1024t begins ======
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;
// ====== int_1024t ends ======

// ====== pbds begins ======
// #include <ext/pb_ds/assoc_container.hpp> 
// #include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
// typedef tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag, 
//         tree_order_statistics_node_update> 
//         pbds; 
// ====== pbds ends ======

// ====== Useful functions begin ======
inline ll add(ll a,ll b) {return ((a%mod)+(b%mod))%mod;}
inline ll sub(ll a,ll b) {return ((a%mod)-(b%mod)+mod)%mod;}
inline ll mul(ll a,ll b) {return ((a%mod)*(b%mod))%mod;}
ll pwr(ll x,ll n){
    if(!n) return 1;
    if(n&1) return mul(x, pwr(mul(x,x),(n-1)/2));
    else return pwr(mul(x,x),n/2);
}
ll modinv(ll n){ 
    return pwr(n,mod - 2); 
}
// ====== Useful functions end ======
 
// ====== Variables begin ======
set <ll> v;
ll k;
// ====== Variables end ======
void speed_solve(){
	cin >> k;
	queue <string> st;
	rep(i,9){
		char c = '0' + i + 1;
		string t(1,c);
		st.push(t);
	}
	ll cnt = 1;
	while(sz(st))
	{
	   ll size = sz(st);
	   rep(i,size){
	       string t = st.front();
	       st.pop();
	       if(cnt == k){
	           cout << t;
	           return;
	       }
	       cnt++;
	       ll last = t.back() - '0';
	        if(last){
	           st.push(t + char(last - 1 + '0'));
	        }
	        st.push(t + char('0' + last));
	        if(last < 9){
	            st.push(t + char(last + 1 + '0'));
	        }
	   }
	}
}
int main()
{
    speed_cubing;
    ll test_cases = 1;
    // cin >> test_cases;
    rep(i,test_cases){
        // cout << "Case #" << i + 1 << ": ";
        speed_solve();
    }
    return 0;
}

Measured memory_bytes: 13824