Buggy python submission (verdict: Time Limit Exceeded):
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7
# s=正の数、t=負の数
s,t = [], []
for a in A:
  if a<0:
    t.append(a)
  else:
    s.append(a)

S = len(s)
T = len(t)
ok = False
if (S>0):
  if n==k:
    # すべての負の数をペアにできる
    ok = T%2==0
  else:
    # 負の数は考慮しない
    ok = True
else:
  # kが偶数個
  ok = (k%2==0)

ans = 1
if not ok:
  A.sort(key=lambda x: abs(x))
  for i in range(k):
    ans *= A[i]
else:
  s.sort()
  t.sort(reverse=True)
  if k%2==1:
    ans *= s.pop()

  p = []
  while len(s) >= 2:
    x = s.pop()
    x *= s.pop()
    p.append(x)

  while len(t) >= 2:
    x = t.pop()
    x *= t.pop()
    p.append(x)

  p.sort(reverse=True)
  for i in range(k//2):
    ans *= p[i]

print(ans % MOD)

Fixed submission:
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7
# s=正の数、t=負の数
s,t = [], []
for a in A:
  if a<0:
    t.append(a)
  else:
    s.append(a)

S = len(s)
T = len(t)
ok = False
if (S>0):
  if n==k:
    # すべての負の数をペアにできる
    ok = T%2==0
  else:
    # 負の数は考慮しない
    ok = True
else:
  # kが偶数個
  ok = (k%2==0)

ans = 1
if not ok:
  A.sort(key=lambda x: abs(x))
  for i in range(k):
    ans *= A[i]
    ans %= MOD
else:
  s.sort()
  t.sort(reverse=True)
  if k%2==1:
    ans *= s.pop()
    ans %= MOD

  p = []
  while len(s) >= 2:
    x = s.pop()
    x *= s.pop()
    p.append(x)

  while len(t) >= 2:
    x = t.pop()
    x *= t.pop()
    p.append(x)

  p.sort(reverse=True)
  for i in range(k//2):
    ans *= p[i]
    ans %= MOD

print(ans % MOD)

Buggy python submission (verdict: Runtime Error):
import bisect
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7

if k==n:
  res = 1
  for a in A:
    res *= a
  print(res % MOD)
elif k%2==1 and all([ a<0 for a in A ]):
  A.sort(reverse=True)
  res = 1
  for i in range(k):
    res *= A[i]
  print(res % MOD)
else:
  absSorted = sorted(A,key=lambda x: abs(x), reverse=True)
  res = 1
  plus = Counter()
  minus = Counter()
  for i in range(k):
    res *= absSorted[i]
    if absSorted[i] < 0:
      minus[absSorted[i]] += 1
    else:
      plus[absSorted[i]] += 1

  if res < 0:
    counter = Counter(A)
    # (1) 負の数の中で絶対値が一番小さいものを1つ取り除き、非負の数の中で最大のものを一つ加える
    minusKeys = sorted(minus.keys(), reverse=True)
    tmp1 = res // minusKeys[0]
    for k in sorted(counter.keys(), reverse=True):
      if plus[k] < counter[k]:
        tmp1 *= k
        break

    # (2) 正の数を1つ取り除き、負の数を一つ加える
    plusKeys = sorted(plus.keys())
    tmp2 = res // plusKeys[0]
    for k in sorted(counter.keys()):
      if minus[k] < counter[k]:
        tmp2 *= k
        break

    print(max(tmp1, tmp2) % MOD)
  else:
    print(res)

Fixed submission:
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7
# s=正の数、t=負の数
s,t = [], []
for a in A:
  if a<0:
    t.append(a)
  else:
    s.append(a)

S = len(s)
T = len(t)
ok = False
if (S>0):
  if n==k:
    # すべての負の数をペアにできる
    ok = T%2==0
  else:
    # 負の数は考慮しない
    ok = True
else:
  # kが偶数個
  ok = (k%2==0)

ans = 1
if not ok:
  A.sort(key=lambda x: abs(x))
  for i in range(k):
    ans *= A[i]
    ans %= MOD
else:
  s.sort()
  t.sort(reverse=True)
  if k%2==1:
    ans *= s.pop()
    ans %= MOD

  p = []
  while len(s) >= 2:
    x = s.pop()
    x *= s.pop()
    p.append(x)

  while len(t) >= 2:
    x = t.pop()
    x *= t.pop()
    p.append(x)

  p.sort(reverse=True)
  for i in range(k//2):
    ans *= p[i]
    ans %= MOD

print(ans % MOD)

Buggy python submission (verdict: Runtime Error):
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7

cumsum = [1]
for a in A:
  cumsum.append(cumsum[-1]*a)

res = -10**16
for i in range(k, n+1):
  res = max(res, cumsum[i]//cumsum[i-k])

print(res%MOD)

Fixed submission:
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7
# s=正の数、t=負の数
s,t = [], []
for a in A:
  if a<0:
    t.append(a)
  else:
    s.append(a)

S = len(s)
T = len(t)
ok = False
if (S>0):
  if n==k:
    # すべての負の数をペアにできる
    ok = T%2==0
  else:
    # 負の数は考慮しない
    ok = True
else:
  # kが偶数個
  ok = (k%2==0)

ans = 1
if not ok:
  A.sort(key=lambda x: abs(x))
  for i in range(k):
    ans *= A[i]
    ans %= MOD
else:
  s.sort()
  t.sort(reverse=True)
  if k%2==1:
    ans *= s.pop()
    ans %= MOD

  p = []
  while len(s) >= 2:
    x = s.pop()
    x *= s.pop()
    p.append(x)

  while len(t) >= 2:
    x = t.pop()
    x *= t.pop()
    p.append(x)

  p.sort(reverse=True)
  for i in range(k//2):
    ans *= p[i]
    ans %= MOD

print(ans % MOD)

Buggy python submission (verdict: Runtime Error):
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7

cumsum = [1]
for a in A:
  cumsum.append(cumsum[-1]*a)

res = -10**16
for i in range(k, n+1):
  res = max(res, cumsum[i]//cumsum[i-k])

print(res%MOD)

Fixed submission:
n,k = map(int,input().split())
A = list(map(int,input().split()))
MOD = 10**9+7
# s=正の数、t=負の数
s,t = [], []
for a in A:
  if a<0:
    t.append(a)
  else:
    s.append(a)

S = len(s)
T = len(t)
ok = False
if (S>0):
  if n==k:
    # すべての負の数をペアにできる
    ok = T%2==0
  else:
    # 負の数は考慮しない
    ok = True
else:
  # kが偶数個
  ok = (k%2==0)

ans = 1
if not ok:
  A.sort(key=lambda x: abs(x))
  for i in range(k):
    ans *= A[i]
    ans %= MOD
else:
  s.sort()
  t.sort(reverse=True)
  if k%2==1:
    ans *= s.pop()
    ans %= MOD

  p = []
  while len(s) >= 2:
    x = s.pop()
    x *= s.pop()
    p.append(x)

  while len(t) >= 2:
    x = t.pop()
    x *= t.pop()
    p.append(x)

  p.sort(reverse=True)
  for i in range(k//2):
    ans *= p[i]
    ans %= MOD

print(ans % MOD)