#include <iostream>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;

char pt0 = 'k';
char pt1 = 'l';

void step() {
  pt1++;
  if (pt1 > 'z') {
    pt0++;
    pt1 = pt0 + 1;
  }
}

string foo() {
  string ret;
  if (pt0 > 'k') ret += pt0;
  ret += pt1;
  return ret;
}

string bar() {
  step();
  return foo();
}

string solve(int n) {
  if (n == 1) return bar();
  if (n % 2 == 0) {
    string s = solve(n / 2);
    string t = foo();
    return t + s + t;
  } else {
    string s = solve(n - 1);
    string t = bar();
    return t + s + t;
  }
}

int main() {
  int n;
  cin >> n;
  cout << solve(n) << endl;
}