#!/usr/bin/env python3





def number_to_alphabet(number):

    if number <= 26:

        return chr(96 + number)



    if number % 26 == 0:

        return number_to_alphabet(number // 26 - 1) + 'z'



    return number_to_alphabet(number // 26) + chr(96 + number % 26)





N = int(eval(input()))

result = number_to_alphabet(N)

print(result)

#!/usr/bin/env python3





def f(n):

    if n == 0:

        return ''



    n -= 1

    return f(n // 26) + chr(ord('a') + n % 26)





N = int(eval(input()))

print((f(N)))

#!/usr/bin/env python3
def number_to_alphabet(number):
    if number <= 26:
        return chr(96 + number)
    if number % 26 == 0:
        return number_to_alphabet(number // 26 - 1) + "z"
    return number_to_alphabet(number // 26) + chr(96 + number % 26)


N = int(eval(input()))
result = number_to_alphabet(N)
print(result)

#!/usr/bin/env python3
def f(n):
    if n == 0:
        return ""
    n -= 1
    return f(n // 26) + chr(ord("a") + n % 26)


N = int(eval(input()))
print((f(N)))

-def number_to_alphabet(number): -    if number <= 26: -        return chr(96 + number) -    if number % 26 == 0: -        return number_to_alphabet(number // 26 - 1) + "z" -    return number_to_alphabet(number // 26) + chr(96 + number % 26) +def f(n): +    if n == 0: +        return "" +    n -= 1 +    return f(n // 26) + chr(ord("a") + n % 26) -result = number_to_alphabet(N) -print(result) +print((f(N)))