n = int(input())
ans = []

ok = int(n**0.5)
for i in range(2*ok-1):
    ans.append(97+i%2)
n -= ok*ok

ok = int(n**0.5)
for i in range(2*ok-1):
    ans.append(100+i%2)
n -= ok*ok

for i in range(n):
    ans.append(120+i%3)

print("".join(map(chr,ans)))