n = int(input())

s = "abcdefghijklmnopqrstuvwxyz"

ans = []



t = 1



while n > 26:

    tmp = n % 26

    if tmp == 0:

        tmp = 26

        n //= 26

        n -= 1

        ans.append(tmp)

        continue

    ans.append(tmp)

    n //= 26



ans.append(n)



for i in ans[::-1]:

    print(s[i-1], end="")

n = int(input())

s = "abcdefghijklmnopqrstuvwxyz"

ans = []



while n > 26:

    n -= 1

    tmp = n % 26

    ans.append(tmp)

    n //= 26



ans.append(n-1)



for i in ans[::-1]:

    print(s[i], end="")

n = int(input())
s = "abcdefghijklmnopqrstuvwxyz"
ans = []
t = 1
while n > 26:
    tmp = n % 26
    if tmp == 0:
        tmp = 26
        n //= 26
        n -= 1
        ans.append(tmp)
        continue
    ans.append(tmp)
    n //= 26
ans.append(n)
for i in ans[::-1]:
    print(s[i - 1], end="")

n = int(input())
s = "abcdefghijklmnopqrstuvwxyz"
ans = []
while n > 26:
    n -= 1
    tmp = n % 26
    ans.append(tmp)
    n //= 26
ans.append(n - 1)
for i in ans[::-1]:
    print(s[i], end="")

-t = 1 +    n -= 1 -    if tmp == 0: -        tmp = 26 -        n //= 26 -        n -= 1 -        ans.append(tmp) -        continue -ans.append(n) +ans.append(n - 1) -    print(s[i - 1], end="") +    print(s[i], end="")