import java.util.Scanner

object Problem254 {

  // 好きな寿司ネタは寒ブリ
  def main(args: Array[String]) = {
    val sc = new Scanner(System.in)
    val n = sc.nextInt

    val sb = new StringBuilder
    var remain = n
    var charIndex = 0
    while (remain > 0) {
      val len = binarySearch(ABPalindrome, remain, 1, 65000)
      remain -= ABPalindrome(len)

      val subPalindrome = getABString(len, charIndex)
      sb.append(subPalindrome)
      charIndex += 2
    }
    println(sb.toString)
  }

  /*
  len以下の（偶数 or 奇数）の和
  6 abab 4 2
  9 ababa 5 3 1
  12 ababab 6 4 2
  16 abababa 7 5 3 1
  20 abababab 8 6 4 2
  25 ababababa 9 7 5 3 1
  */
  def ABPalindrome(n: Int): Int = {
    n % 2 match {
      case 0 => (n / 2) * (n / 2 + 1)
      case 1 => Math.pow((n / 2 + 1), 2).toInt
    }
  }

  def binarySearch(f: Int => Int, n: Int, low: Int, high: Int): Int = {
    val mid = (low + high) / 2

    if (low > high) {
      return mid
    }

    (f(mid), n) match {
      case (x, y) if x == y => mid
      case (x, y) if x < y => binarySearch(f, n, mid + 1, high)
      case _ => binarySearch(f, n, low, mid - 1)
    }
  }

  def getABString(len: Int, charIndex: Int): String = {
    val a = ('a' + charIndex).toChar
    val b = ('b' + charIndex).toChar
    val ab = a.toString + b.toString

    len % 2 match {
      case 0 => ab * (len / 2)
      case 1 => ab * (len / 2) + a
    }
  }

}