Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

for i in range(3,N):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )



Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

for i in range(3,N):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

for i in range(3,N):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*N
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

for i in range(3,N):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*N
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(1000000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]


def cmb(n, r):
    if n - r < r: r = n - r
    if r == 0: return 1
    if r == 1: return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2,r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1,r,p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

# DP version
DP = [0]*N
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(1000000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]


def cmb(n, r):
    if n - r < r: r = n - r
    if r == 0: return 1
    if r == 1: return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2,r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1,r,p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

# DP version
DP = [0]*N
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(100000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]


def cmb(n, r):
    if n - r < r: r = n - r
    if r == 0: return 1
    if r == 1: return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2,r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1,r,p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

# DP version
DP = [0]*N
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(100000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]


def cmb(n, r):
    if n - r < r: r = n - r
    if r == 0: return 1
    if r == 1: return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2,r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1,r,p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

# DP version
DP = [0]*N
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
DP[2] = 2

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Time Limit Exceeded):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(100000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]


def cmb(n, r):
    if n - r < r: r = n - r
    if r == 0: return 1
    if r == 1: return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2,r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1,r,p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Time Limit Exceeded):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

sys.setrecursionlimit(100000)
nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

nCr = {}
def cmb(n, r):
    if r == 0 or r == n: return 1
    if r == 1: return n
    if (n,r) in nCr: return nCr[(n,r)]
    nCr[(n,r)] = cmb(n-1,r) + cmb(n-1,r-1)
    return nCr[(n,r)]

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Time Limit Exceeded):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Time Limit Exceeded):
import sys
#from scipy.special import comb
#from scipy.misc import comb

from operator import mul
from functools import reduce

def cmb(n,r):
    r = min(n-r,r)
    if r == 0: return 1
    over = reduce(mul, range(n, n - r, -1))
    under = reduce(mul, range(1,r + 1))
    return over // under

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            #c += comb(j+i, i, exact=True)
            c += cmb(j+i, i)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
#from scipy.special import comb
from scipy.misc import comb

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            c += comb(j+i, i, exact=True)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Time Limit Exceeded):
import sys
#from scipy.special import comb
from scipy.misc import comb

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1)

def step_comb(L):
    c = 0
    if L==1 or L == 0:
        c = 1
    else:
        for i in range(L//2 +1):
            j = L - 2*i
            c += comb(j+i, i, exact=True)
    return c

total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    
print(total_comb % 1000000007 )


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )

Buggy python submission (verdict: Runtime Error):
import sys
from scipy.special import comb
# a = comb(n, r)
#a = comb(n, r, exact=True)

# L 段の階段を 1 or 2 段上り
# ２段を i 回 (i<L//2) 1段を j 回 (j = L - 2*i)
# L odd の場合
# i = 0~L//2

N,M = list(map(int, input().split()))

A = [0]*M

for i in range(M):
    A[i] = int(input())

A.append(N+1) # goal

total_combo = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    combo = 0
    for i in range(L//2 +1):
        j = L - 2*i
        combo += comb(j+1, i, exact=True)
    total_combo *= combo
    NOW = a + 1
    
print(total_combo)


Fixed submission:
import sys
sys.setrecursionlimit(100000000)

N,M = list(map(int, input().split()))

if M == 0:
    A = []
else:
    A = [0]*M
    for i in range(M):
        A[i] = int(input())

A.append(N+1)

# DP version
DP = [0]*(N+1)
DP[0] = 1
# １段の階段を登るやり方の数
DP[1] = 1
# 2段の階段を登るやり方の数
#DP[2] = 2

for i in range(2,N+1):
    DP[i] = DP[i-1] + DP[i-2]

def step_comb(L):
    if DP[L]>0:
        return DP[L]
    DP[L] = step_comb(L-1) + step_comb(L-2)
    return DP[L]
    
total_comb = 1
NOW = 0
for a in A:
    if NOW == a:
        print(0)
        sys.exit()
    L = a-1-NOW
    total_comb *= step_comb(L)
    NOW = a + 1
    if NOW == N:
        break
    
print(total_comb % 1000000007 )