#include <bits/stdc++.h>
using namespace std;

int main()
{
	int N;
	cin >> N;
	queue<string> q;
	for( int i = 1; i < 10; i++ ) {
		for( int j = i + 1; j < 10; j++ ) q.push( to_string(i * 10 + j) );
	}
	string ans;
	while( N ) {
		ans = q.front();
		q.pop();
		q.push( ans + ans.back() );
		N--;
	}
	cout << ans << endl;
}