#!/usr/bin/env python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import itertools

N = int(read())

alphabets = []
for x, y in itertools.product(range(1, 26), repeat=2):
    alphabets.append('a' + chr(ord('a') + x) + chr(ord('a') + y))


def f(N):
    a = alphabets.pop()
    if N == 1:
        return a
    if N == 2:
        return a + a
    if N & 1:
        return a + f(N - 1) + a
    return a + a + f((N - 2) // 2) + a + a


print(f(N))