#include <bits/stdc++.h>
int main() {
  long long N;
  std::cin >> N;
  std::string name;
  long long keta = 0;
  long long cpyN = N;
  while (cpyN > 0) {
    keta++;
    long long k_value = 1;
    for (int i = 0; i < keta; i++) {
      k_value *= 26;
    }
    char chr = cpyN % k_value;
    if (chr == 0) {
      chr = 26;
    }
    cpyN -= (long long)chr;
    name += chr + (char)96;
    printf("%c\n", chr + (char)96);
  }
  std::reverse(name.begin(), name.end());
  std::cout << name << std::endl;
  return 0;
}
