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

using namespace std;
using ll = long long;
        
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin>>n;
    deque<pair<pair<int,int>,int>> que;
    for(int i = 1;i<=9;i++){
        for(int j = i+1;j<=9;j++){
            que.push_back(make_pair(make_pair(i,j),1));
        }
    }
    while(n>1){
        n--;
        auto now = que.front();
        que.pop_front();
        now.second++;
        que.push_back(now);
    }
    auto now = que.front();
    cout<<now.first.first;
    for(int i = 0;i<now.second;i++) cout<<now.first.second;
    cout<<endl;
}