Buggy python submission (verdict: Runtime Error):
import collections

N = int(input())
D = list(map(int, input().split()))
is_first_zero = True
if D[0] != 0:
    is_first_zero = False
if is_first_zero:
    c = sorted(collections.Counter(D).items(), key=lambda x:x[0])
    #print(c)
    for index, i in enumerate(c):
        ind = i[0]
        num = i[1]
        if ind == 0:
            if num != 1:
                is_first_zero = False
                break
        else:
            if ind != pre_ind + 1:
                is_first_zero = False
                break
            else:
                if index == 2:
                    res = pre_num ** num
                elif index > 2:
                    res = res * (pre_num ** num)
                #print(res)
        pre_ind = ind
        pre_num = num
                
if is_first_zero:
    print(res % 998244353)
else:
    print("0")

Fixed submission:
#B
import collections

N = int(input())
D = list(map(int, input().split()))
is_first_zero = True
if D[0] != 0:
    is_first_zero = False
if is_first_zero:
    c = sorted(collections.Counter(D).items(), key=lambda x:x[0])
    if len(c) == 2:
        res = 1
    for index, i in enumerate(c):
        ind = i[0]
        num = i[1]
        if ind == 0:
            if num != 1:
                is_first_zero = False
                break
        else:
            if ind != pre_ind + 1:
                is_first_zero = False
                break
            else:
                if index == 2:
                    res = pre_num ** num
                elif index > 2:
                    res = res * (pre_num ** num)
                #print(res)
        pre_ind = ind
        pre_num = num
                
if is_first_zero:
    print(res % 998244353)
else:
    print("0")

Buggy python submission (verdict: Runtime Error):
#B
import collections

N = int(input())
D = list(map(int, input().split()))
is_first_zero = True
if D[0] != 0:
    is_first_zero = False
if is_first_zero:
    c = sorted(collections.Counter(D).items(), key=lambda x:x[0])
    #print(c)
    for index, i in enumerate(c):
        ind = i[0]
        num = i[1]
        if ind == 0:
            if num != 1:
                is_first_zero = False
                break
        else:
            if ind != pre_ind + 1:
                is_first_zero = False
                break
            else:
                if index == 2:
                    res = pre_num ** num
                elif index > 2:
                    res = res * (pre_num ** num)
                #print(res)
        pre_ind = ind
        pre_num = num
                
if is_first_zero:
    print(res)
else:
    print("0")

Fixed submission:
#B
import collections

N = int(input())
D = list(map(int, input().split()))
is_first_zero = True
if D[0] != 0:
    is_first_zero = False
if is_first_zero:
    c = sorted(collections.Counter(D).items(), key=lambda x:x[0])
    if len(c) == 2:
        res = 1
    for index, i in enumerate(c):
        ind = i[0]
        num = i[1]
        if ind == 0:
            if num != 1:
                is_first_zero = False
                break
        else:
            if ind != pre_ind + 1:
                is_first_zero = False
                break
            else:
                if index == 2:
                    res = pre_num ** num
                elif index > 2:
                    res = res * (pre_num ** num)
                #print(res)
        pre_ind = ind
        pre_num = num
                
if is_first_zero:
    print(res % 998244353)
else:
    print("0")