Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    cnt = 0
    MOD = 10**9 + 7

    for pm in permutations(range(N)):
        goal = [False] * N
        flag = True

        for k in pm:
            mae = 0
            for i in range(k):
                if goal[i]:
                    continue
                
                if X[i] < 2*mae + 1:
                    flag = False
                    break
                else:
                    mae += 1

            if not flag:
                break

            goal[k] = True

        cnt += flag

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    cnt = 0
    MOD = 10**9 + 7

    for pm in permutations(range(N)):
        goal = [False] * N
        flag = True

        for p in pm:
            for i in range(p-1, -1, -1):
                if goal[i]:
                    continue
                if X[i] < 2*i + 1:
                    flag = False
                    break
            if flag:
                break
            goal[p] = True

        cnt += flag

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    cnt = 0
    MOD = 10**9 + 7

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, -1, -1):
                if Xc[i] < 2*i + 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = float('inf')

        cnt += flag

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    cnt = 0
    MOD = 10**9 + 7

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, 0, -1):
                if Xc[i] < 2*i + 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = float('inf')
            k += 1

        cnt += flag

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    for i in range(N - 1):
        if X[i] + 1 == X[i + 1] and X[i] > 1 and X[i-1] < X[i] - 1:
            X[i] -= 1
    cnt = 0
    MOD = 10**9 + 7
    k = 0

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, 0, -1):
                if Xc[i] == Xc[i - 1] + 1 and Xc[i - 1] == 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = -(1 + 2*k)
            k += 1

        cnt += flag

        # if flag:
            # print(list(pm))

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    for i in range(N - 1):
        if X[i] + 1 == X[i + 1] and X[i] > 1 and X[i-1] < X[i] - 1:
            X[i] -= 1
    cnt = 0
    MOD = 10**9 + 7
    k = 0

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, 0, -1):
                if Xc[i] == Xc[i - 1] + 1 and Xc[i - 1] == 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = -(1 + 2*i)
            k += 1

        cnt += flag

        # if flag:
            # print(list(pm))

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    for i in range(N - 1):
        if X[i] + 1 == X[i + 1] and X[i] > 1 and X[i-1] < X[i] - 1:
            X[i] -= 1
    cnt = 0
    MOD = 10**9 + 7
    i = 0

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, 0, -1):
                if Xc[i] == Xc[i - 1] + 1 and Xc[i - 1] == 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = -(1 + 2*i)
            i += 1

        cnt += flag

        # if flag:
            # print(list(pm))

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Runtime Error):
import sys
from itertools import permutations

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    assert N <= 8

    X = [int(i) for i in input().split()]

    for i in range(N - 1):
        if X[i] + 1 == X[i + 1] and X[i] > 1 and X[i-1] < X[i] - 1:
            X[i] -= 1
    cnt = 0
    MOD = 10**9 + 7

    for pm in permutations(range(N)):
        Xc = X[:]
        flag = True

        for p in pm:
            for i in range(p-1, 0, -1):
                if Xc[i] == Xc[i - 1] + 1 and Xc[i - 1] == 1:
                    flag = False
                    break
            if flag:
                break
            Xc[p] = -1

        cnt += flag

        # if flag:
            # print(list(pm))

    print(cnt % MOD)


if __name__ == '__main__':
    solve()

Fixed submission:
import sys
from math import factorial

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    N = int(input())
    X = [int(i) for i in input().split()]
    MOD = 10**9 + 7
    ans = 1
    stack = 0

    for x in X:
        stack += 1
        if x < 2*(stack - 1) + 1:
            ans *= stack
            ans %= MOD
            stack -= 1

    ans *= (factorial(stack) % MOD)
    ans %= MOD

    print(ans)


if __name__ == '__main__':
    solve()