n=int(eval(input()))

x=1

X='abcdefghijklmnopqrstuvwxyz'

for i in range(1,100):

    if x<=n<x+26**i:

        n-=x

        cnt=i

        break

    else:

        x+=26**i

ans=''

for i in reversed(list(range(cnt))):

    ans+=X[n//(26**i)]

    n%=(26**i)

print(ans)
n=int(eval(input()))

x=1

X='abcdefghijklmnopqrstuvwxyz'

for i in range(1,100):

    if x<=n<x+26**i:

        n-=x

        cnt=i

        break

    else:

        x+=26**i

ans=''

for i in range(cnt):

    ans=ans+X[n%26]

    n//=26



print((ans[::-1]))
n = int(eval(input()))
x = 1
X = "abcdefghijklmnopqrstuvwxyz"
for i in range(1, 100):
    if x <= n < x + 26**i:
        n -= x
        cnt = i
        break
    else:
        x += 26**i
ans = ""
for i in reversed(list(range(cnt))):
    ans += X[n // (26**i)]
    n %= 26**i
print(ans)

n = int(eval(input()))
x = 1
X = "abcdefghijklmnopqrstuvwxyz"
for i in range(1, 100):
    if x <= n < x + 26**i:
        n -= x
        cnt = i
        break
    else:
        x += 26**i
ans = ""
for i in range(cnt):
    ans = ans + X[n % 26]
    n //= 26
print((ans[::-1]))

-for i in reversed(list(range(cnt))): -    ans += X[n // (26**i)] -    n %= 26**i -print(ans) +for i in range(cnt): +    ans = ans + X[n % 26] +    n //= 26 +print((ans[::-1]))