n = int(eval(input()))

ans = ''

for i in range(1, 99):

    if n <= 26 ** i:

        n -= 1

        for j in range(i):

            ans += chr(ord('a') + n%26)

            n //= 26

        break

    else:

        n -= 26 ** i

print((ans[::-1]))
n = int(eval(input()))

ans = ''

while n>0:

    n -= 1

    ans += chr(ord('a') + n%26)

    n //= 26

print((ans[::-1]))
n = int(eval(input()))
ans = ""
for i in range(1, 99):
    if n <= 26**i:
        n -= 1
        for j in range(i):
            ans += chr(ord("a") + n % 26)
            n //= 26
        break
    else:
        n -= 26**i
print((ans[::-1]))

n = int(eval(input()))
ans = ""
while n > 0:
    n -= 1
    ans += chr(ord("a") + n % 26)
    n //= 26
print((ans[::-1]))

-for i in range(1, 99): -    if n <= 26**i: -        n -= 1 -        for j in range(i): -            ans += chr(ord("a") + n % 26) -            n //= 26 -        break -    else: -        n -= 26**i +while n > 0: +    n -= 1 +    ans += chr(ord("a") + n % 26) +    n //= 26