Buggy python submission (verdict: Runtime Error):
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n+1)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for index in range(n-1)[::-1]:
  i = index + 1
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

print(int(f[0]%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)

Buggy python submission (verdict: Time Limit Exceeded):
n, m  = map(int, input().split())
alist = [int(input()) for i in range(m)]
div_num = 1000000007

f = [1, 1]
for i in range(n-1)[::-1]:
  flag1 = True if i+1 not in alist else False
  flag2 = True if i+2 not in alist else False
  if flag1 is False and flag2 is False:
    print(0)
    exit()
  elif flag1 is False and flag2 is True:
    f = [f[1]] + [f[0]]
  elif flag1 is True and flag2 is False:
    f = [f[0]] + [f[0]]
  else:
    f = [f[0]+f[1]] + [f[0]]
     
print(int(f[0]%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)

Buggy python submission (verdict: Runtime Error):
n, m  = map(int, input().split())
alist = [int(input()) for i in range(m)]
div_num = 1000000007

f = [1, 1]
for i in range(n-1)[::-1]:
  flag1 = True if i+1 not in alist else False
  flag2 = True if i+2 not in alist else False
  if flag1 is False and flag2 is False:
    print(0)
    exit()
  elif falg1 is False and flag2 is True:
    f = [f[1]] + [f[0]]
  elif flag1 is True and flag2 is False:
    f = [f[0]] + [f[0]]
  else:
    f = [f[0]+f[1]] + [f[0]]
     
print(int(f[0]%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)

Buggy python submission (verdict: Time Limit Exceeded):
n, m  = map(int, input().split())
alist = [int(input()) for i in range(m)]
div_num = 1000000007

f = [1, 1]
for i in range(n-1)[::-1]:
  if i+1 in alist and i+2 in alist:
    print(0)
    exit()
  elif i+1 in alist and i+2 not in alist:
    f = [f[1]] + [f[0]]
  elif i+1 not in alist and i+2 in alist:
    f = [f[0]] + [f[0]]
  else:
    f = [f[0]+f[1]] + [f[0]]
     
print(int(f[0]%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)

Buggy python submission (verdict: Runtime Error):
from math import factorial

def cases(idx_start, idx_end):
  cases = 0
  for r in range((idx_end - idx_start)//2+1):
    n = idx_end - idx_start - r
    cases += factorial(n) / factorial(r) / factorial(n - r)
  return cases

n, m  = map(int, input().split())
alist = [int(input()) for i in range(m)]
div_num = 1000000007

if m == 0:
  print(cases(1,n+1)%div_num)
  exit()

ans = cases(1,alist[0])
for i in range(1,m):
  if alist[i] - alist[i-1] <= 1:
    print(0)
    exit()
  ans *= cases(alist[i-1]+1, alist[i])
ans *= cases(alist[-1]+1, n+1)
print(int(ans%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)

Buggy python submission (verdict: Runtime Error):
from math import factorial

def cases(idx_start, idx_end):
  cases = 0
  for r in range((idx_end - idx_start)//2+1):
    n = idx_end - idx_start - r
    cases += factorial(n) / factorial(r) / factorial(n - r)
  return cases

n, m  = map(int, input().split())
alist = [int(input()) for i in range(m)]
div_num = 1000000007

ans = cases(1,alist[0])
for i in range(1,m):
  if alist[i] - alist[i-1] <= 1:
    print(0)
    exit()
  ans *= cases(alist[i-1]+1, alist[i])
ans *= cases(alist[-1]+1, n+1)
print(int(ans%div_num))

Fixed submission:
n, m  = map(int, input().split())

if n == 1:
  print(1)
  exit()

f = [0 for i in range(n)]
f[-2:] = [1, 1]
for i in range(m):
  f[int(input())-1] = -1

div_num = 1000000007

for i in range(n-2)[::-1]:
  if f[i] == -1:
    continue
  if f[i+1] == -1 and f[i+2] == -1:
    print(0)
    exit()
  elif f[i+1] == -1 and f[i+2] != -1:
    f[i] = f[i+2]
  elif f[i+1] != -1 and f[i+2] == -1:
    f[i] = f[i+1]
  else:
    f[i] = f[i+1]+f[i+2]

if f[0] != -1 and f[1] != -1:
  print(int((f[0]+f[1])%div_num))
elif f[0] == -1 and f[1] != -1:
  print(int(f[1]%div_num))
elif f[0] != -1 and f[1] == -1:
  print(int(f[0]%div_num))
else:
  print(0)