N = int(eval(input()))

ans = ""

while N > 0:

    N -= 1

    ans += chr(97 + N%26)

    N //= 26

print((ans[::-1]))
def f(N):

    if N == 0: return ""

    N -= 1

    return f(N//26) + chr(97 + N%26)



N = int(eval(input()))

print((f(N)))
N = int(eval(input()))
ans = ""
while N > 0:
    N -= 1
    ans += chr(97 + N % 26)
    N //= 26
print((ans[::-1]))

def f(N):
    if N == 0:
        return ""
    N -= 1
    return f(N // 26) + chr(97 + N % 26)


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

+def f(N): +    if N == 0: +        return "" +    N -= 1 +    return f(N // 26) + chr(97 + N % 26) + + -ans = "" -while N > 0: -    N -= 1 -    ans += chr(97 + N % 26) -    N //= 26 -print((ans[::-1])) +print((f(N)))