n = int(eval(input()))

a = 'abcdefghijklmnopqrstuvwxyz'

ans = ''

while n > 0:

    n, r = divmod(n-1, 26)

    ans = a[r] + ans

print(ans)

n = int(eval(input()))

ans = ''

while n > 0:

    n, r = divmod(n-1, 26)

    ans = chr(r+ord('a')) + ans

print(ans)

n = int(eval(input()))
a = "abcdefghijklmnopqrstuvwxyz"
ans = ""
while n > 0:
    n, r = divmod(n - 1, 26)
    ans = a[r] + ans
print(ans)

n = int(eval(input()))
ans = ""
while n > 0:
    n, r = divmod(n - 1, 26)
    ans = chr(r + ord("a")) + ans
print(ans)

-a = "abcdefghijklmnopqrstuvwxyz" -    ans = a[r] + ans +    ans = chr(r + ord("a")) + ans