Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
if m=0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Fixed submission:
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
if m==0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b%(10**9+7)
if m=0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Fixed submission:
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
if m==0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Fixed submission:
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
if m==0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Buggy python submission (verdict: Runtime Error):
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
    print(c)
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))

Fixed submission:
n,m=map(int,input().split())
a=[int(input()) for _ in range(m)]
def fb(num):
    a,b = 1,0
    for _ in range(num+1):
        a,b = a+b,a
    return b
if m==0:
    print(fb(n)%(10**9+7))
    exit()
if m>1:
    for i in range(m-1):
        if a[i+1]-a[i]==1:
            print(0)
            exit()
c=0
for i in range(m):
    if i==0 and a[0]==1:
        c+=1
    elif i==0:
        c+=fb(a[0]-1)
    else:
        c*=(fb(a[i]-a[i-1]-2)%(10**9+7))
c*=fb(n-a[-1]-1)%(10**9+7)
print(c%(10**9+7))