Buggy python submission (verdict: Runtime Error):
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 >= N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
num = [0 for _ in range(n)]

for i in range(n):
  ii = n-i
  for j in range(1,27):
    if 26**(ii-1) * j >= N:
      if i != n-1:
        num[i] = alpha[j-2]
      else:
        num[i] = alpha[j-1]
      N -= 26**(ii-1) * (j-1)
      break

print(''.join(num))

Fixed submission:
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 >= N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
num = []

num = [0 for _ in range(n)]

for i in reversed(range(n)):
  for j in range(1,27):
    pre = 26*(26**i-1)/25
    if 26**i * j + pre >= N:
      num[i] = alpha[j-1]

      N -= 26**i * j
      break


print(''.join(num[::-1]))

Buggy python submission (verdict: Runtime Error):
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 > N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']


num = [0 for _ in range(n)]
for i in range(n):
  ii = n-i
  for j in range(1,27):
    if 26**(ii-1) * j > N:
      num[i] = alpha[j-2]
      N -= 26**(ii-1) * (j-1)
      break

print(''.join(num))

Fixed submission:
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 >= N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
num = []

num = [0 for _ in range(n)]

for i in reversed(range(n)):
  for j in range(1,27):
    pre = 26*(26**i-1)/25
    if 26**i * j + pre >= N:
      num[i] = alpha[j-1]

      N -= 26**i * j
      break


print(''.join(num[::-1]))

Buggy python submission (verdict: Runtime Error):
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 > N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']


num = [0 for _ in range(n)]
for i in range(n):
  ii = n-i
  for j in range(1,27):
    if 26**(ii-1) * j > N:
      num[i] = alpha[j-2]
      N -= 26**(ii-1) * (j-1)
      break

print(''.join(num))

Fixed submission:
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 >= N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
num = []

num = [0 for _ in range(n)]

for i in reversed(range(n)):
  for j in range(1,27):
    pre = 26*(26**i-1)/25
    if 26**i * j + pre >= N:
      num[i] = alpha[j-1]

      N -= 26**i * j
      break


print(''.join(num[::-1]))

Buggy python submission (verdict: Runtime Error):
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 > N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']


num = [0 for _ in range(n)]
for i in range(n):
  ii = n-i
  for j in range(1,27):
    if 26**(ii-1) * j > N:
      num[i] = alpha[j-2]
      N -= 26**(ii-1) * (j-1)
      break

print(''.join(num))

Fixed submission:
n = 1
N = int(input())

while True:
  if  26*(26**n-1)/25 >= N:
    break
  else:
    n +=1

alpha = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
num = []

num = [0 for _ in range(n)]

for i in reversed(range(n)):
  for j in range(1,27):
    pre = 26*(26**i-1)/25
    if 26**i * j + pre >= N:
      num[i] = alpha[j-1]

      N -= 26**i * j
      break


print(''.join(num[::-1]))