Buggy python submission (verdict: Runtime Error):
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(map(int,input().split()))
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7

N = i()
A = [26**i for i in range(1,100)]
A = [0]+list(itertools.accumulate(A))
cnt = 0
for i in range(N):
    if A[i] >= N:
        p = cnt
        break
    cnt += 1
if p == 1:
    print(chr(N+96))
    exit()
s = []
if N in A:
    print('z'*p)
    exit()
for i in range(p):
    m = chr(N%26+96)
    if m == '`':
        m = 'a'
    s.append(m)
    N = N//26
s.reverse()
print(''.join(s))

Fixed submission:
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
mod = 10**9+7

N = i()
S = []
for i in range(1,100):
    if N < 27:
        break
    N -= 1
    S.append(chr(ord('a')+N%26))
    N = N//26
S.append(chr(ord('a')+N-1))
print(''.join(S[::-1]))

Buggy python submission (verdict: Runtime Error):
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(map(int,input().split()))
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7

N = i()
A = [26**i for i in range(1,100)]
A = [0]+list(itertools.accumulate(A))
cnt = 0
for i in range(N):
    if A[i] >= N:
        p = cnt
        break
    cnt += 1
if p == 1:
    print(chr(N+96))
    exit()
s = []
if N in A:
    print('z'*p)
    exit()
for i in range(p-1):
    m = chr(N%26+96)
    if m == '`':
        m = 'a'
    s.append(m)
    N = N//26
s.append(chr(N+96))
s.reverse()
print(''.join(s))

Fixed submission:
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
mod = 10**9+7

N = i()
S = []
for i in range(1,100):
    if N < 27:
        break
    N -= 1
    S.append(chr(ord('a')+N%26))
    N = N//26
S.append(chr(ord('a')+N-1))
print(''.join(S[::-1]))

Buggy python submission (verdict: Runtime Error):
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(map(int,input().split()))
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7

N = i()
A = [26**i for i in range(1,100)]
A = [0]+list(itertools.accumulate(A))
cnt = 0
for i in range(N):
    if A[i] >= N:
        p = cnt
        break
    cnt += 1
if p == 1:
    print(chr(N+96))
    exit()
s = []
if N in A:
    print('z'*p)
    exit()
for i in range(p-1):
    m = chr(N%26+96)
    if m == '`':
        m = 'a'
    s.append(m)
    N = N//26
    print(N%26)
s.append(chr(N+96))
s.reverse()
print(''.join(s))

Fixed submission:
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
mod = 10**9+7

N = i()
S = []
for i in range(1,100):
    if N < 27:
        break
    N -= 1
    S.append(chr(ord('a')+N%26))
    N = N//26
S.append(chr(ord('a')+N-1))
print(''.join(S[::-1]))

Buggy python submission (verdict: Runtime Error):
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(map(int,input().split()))
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7

N = i()
A = [26**i for i in range(1,100)]
A = [0]+list(itertools.accumulate(A))
cnt = 0
for i in range(N):
    if A[i] >= N:
        p = cnt
        break
    cnt += 1
if p == 1:
    print(chr(N+96))
    exit()
s = []
if N in A:
    print('z'*p)
    exit()
for i in range(p-1):
    if N%26 == 0:
        s.append(chr(97))
    else:
        s.append(chr(N%26+96))
    N = N//26
    print(N%26)
s.append(chr(N+96))
s.reverse()
print(''.join(s))

Fixed submission:
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
mod = 10**9+7

N = i()
S = []
for i in range(1,100):
    if N < 27:
        break
    N -= 1
    S.append(chr(ord('a')+N%26))
    N = N//26
S.append(chr(ord('a')+N-1))
print(''.join(S[::-1]))

Buggy python submission (verdict: Runtime Error):
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(map(int,input().split()))
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7

N = i()
A = [26**i for i in range(1,30)]
A = [0]+list(itertools.accumulate(A))
cnt = 0
for i in range(N):
    if A[i] >= N:
        p = cnt
        break
    cnt += 1
if p == 1:
    print(chr(N+96))
s = []
if N in A:
    print('z'*p)
    exit()
for i in range(p-1):
    s.append(chr(N%26+96))
    N = N//26
s.append(chr(N+96))
s.reverse()
print(''.join(s))

Fixed submission:
import sys
import math
import itertools
import bisect
from copy import copy
from collections import deque,Counter
from decimal import Decimal
def s(): return input()
def i(): return int(input())
def S(): return input().split()
def I(): return map(int,input().split())
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
mod = 10**9+7

N = i()
S = []
for i in range(1,100):
    if N < 27:
        break
    N -= 1
    S.append(chr(ord('a')+N%26))
    N = N//26
S.append(chr(ord('a')+N-1))
print(''.join(S[::-1]))