N = int(eval(input()))

alphabets = {i: chr(i + 96) for i in range(1, 26)}

alphabets[0] = 'z'



queue = []

if N <= 26:

    print((alphabets[N]))

else:

    while N > 0:

        queue.insert(0, alphabets[N % 26])

        N -= 1

        N //= 26



    print((''.join(queue)))
N = int(eval(input()))

alphabets = {i: chr(i + 96) for i in range(1, 26)}

alphabets[0] = 'z'



queue = []



while N > 0:

    queue.insert(0, alphabets[N % 26])

    N -= 1

    N //= 26



print((''.join(queue)))
N = int(eval(input()))
alphabets = {i: chr(i + 96) for i in range(1, 26)}
alphabets[0] = "z"
queue = []
if N <= 26:
    print((alphabets[N]))
else:
    while N > 0:
        queue.insert(0, alphabets[N % 26])
        N -= 1
        N //= 26
    print(("".join(queue)))

N = int(eval(input()))
alphabets = {i: chr(i + 96) for i in range(1, 26)}
alphabets[0] = "z"
queue = []
while N > 0:
    queue.insert(0, alphabets[N % 26])
    N -= 1
    N //= 26
print(("".join(queue)))

-if N <= 26: -    print((alphabets[N])) -else: -    while N > 0: -        queue.insert(0, alphabets[N % 26]) -        N -= 1 -        N //= 26 -    print(("".join(queue))) +while N > 0: +    queue.insert(0, alphabets[N % 26]) +    N -= 1 +    N //= 26 +print(("".join(queue)))