#include <bits/stdc++.h>
using namespace std;
int sq[1000001];
int main() {
  memset((sq), (0), sizeof(sq));
  for (int i = 0; i * i <= 1000001; i++) sq[i * i] = 1;
  int n;
  scanf("%d", &n);
  int a[3];
  int y = 8 * n + 3;
  for (int i = 0; i * i <= y; i++)
    for (int j = i; j * j + i * i <= y; j++)
      if (sq[y - i * i - j * j] == 1) {
        a[0] = i;
        a[1] = j;
        a[2] = sqrt(y - i * i - j * j);
      }
  a[0] /= 2;
  a[1] /= 2;
  a[2] /= 2;
  for (int i = 0; i <= a[0]; i++) printf("a");
  for (int i = 0; i <= a[1]; i++) printf("b");
  for (int i = 0; i <= a[2]; i++) printf("c");
  printf("\n");
}
