from string import ascii_lowercase


def tmp(N):
    l = 0
    r = 10 ** 6
    while r - l > 1:
        m = (l + r) // 2
        M = m * 2
        if M * (M + 2) // 4 > N:
            r = m
        else:
            l = m
    return l * 2


N = int(input())
ans = ""
L = tmp(N)
for i in range(L):
    if i % 2 == 0:
        ans += "x"
    else:
        ans += "y"
R = N - (L * (L + 2) // 4)
for i in range(R):
    i %= len(ascii_lowercase)
    ans += ascii_lowercase[i]
print(ans)