N = int(input())



s = []

a = 26

tmp = 1

for i in range(20):

    s.append(tmp)

    tmp += a

    a *= 26

    if tmp > 100000000000000000:

        break



for i in range(len(s)):

    if N >= s[i]:

        continue

    else:

        size = i 

        break



b = N - s[size-1]



n2a = lambda c: chr(c+64)

a = 26 ** (size-1)



ans = []

while(a >= 1):

    ans.append(n2a(b // a + 1).lower())

    b %= a

    a //= 26



print(*ans, sep="")

N = int(eval(input()))

N -= 1



d = 26

for i in range(1,15):

    if N >= d:

        N -= d

        d *= 26

    else:

        d //= 26

        ans = ""

        for j in range(i):

            ans += chr(N // d + ord("a"))

            N %= d

            d //= 26

        break



print(ans)
N = int(input())
s = []
a = 26
tmp = 1
for i in range(20):
    s.append(tmp)
    tmp += a
    a *= 26
    if tmp > 100000000000000000:
        break
for i in range(len(s)):
    if N >= s[i]:
        continue
    else:
        size = i
        break
b = N - s[size - 1]
n2a = lambda c: chr(c + 64)
a = 26 ** (size - 1)
ans = []
while a >= 1:
    ans.append(n2a(b // a + 1).lower())
    b %= a
    a //= 26
print(*ans, sep="")

N = int(eval(input()))
N -= 1
d = 26
for i in range(1, 15):
    if N >= d:
        N -= d
        d *= 26
    else:
        d //= 26
        ans = ""
        for j in range(i):
            ans += chr(N // d + ord("a"))
            N %= d
            d //= 26
        break
print(ans)

-N = int(input()) -s = [] -a = 26 -tmp = 1 -for i in range(20): -    s.append(tmp) -    tmp += a -    a *= 26 -    if tmp > 100000000000000000: +N = int(eval(input())) +N -= 1 +d = 26 +for i in range(1, 15): +    if N >= d: +        N -= d +        d *= 26 +    else: +        d //= 26 +        ans = "" +        for j in range(i): +            ans += chr(N // d + ord("a")) +            N %= d +            d //= 26 -for i in range(len(s)): -    if N >= s[i]: -        continue -    else: -        size = i -        break -b = N - s[size - 1] -n2a = lambda c: chr(c + 64) -a = 26 ** (size - 1) -ans = [] -while a >= 1: -    ans.append(n2a(b // a + 1).lower()) -    b %= a -    a //= 26 -print(*ans, sep="") +print(ans)