Buggy python submission (verdict: Time Limit Exceeded):
from itertools import starmap
from operator import mul


def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        print(' ' * i, *a)


def first(aaa):
    aaa = list(map(int, aaa))
    aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return aaa


def last(aaa):
    for i in range(len(aaa) - 1):
        aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return aaa[0]


def prepare():
    # for v in product([0, 1, 2], repeat=10):
    ret = [0] * (3 ** 10)
    for i in range(3 ** 10):
        v = i
        v, m1 = divmod(v, 3)
        tmp = []
        for _ in range(9):
            v, m2 = divmod(v, 3)
            tmp.append(abs(m1 - m2))
            m1 = m2
        tmp.reverse()
        for _ in range(8):
            tmp = [abs(a1 - a0) for a0, a1 in zip(tmp, tmp[1:])]
        ret[i] = tmp[0]
    return ret


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 3, 1, 3, 1, 3, 1, 3, 1, 3])

n = int(input())
aaa = input()
aaa = first(aaa)
ppp = prepare()
pow3 = [3 ** (9 - i) for i in range(10)]
while len(aaa) >= 10:
    aaa = [ppp[sum(starmap(mul, zip(aaa[i:i + 10], pow3)))] for i in range(len(aaa) - 9)]
ans = last(aaa)
print(ans)


Fixed submission:
def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        # print(' ' * i, *a)
        print(*a)


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 2, 0, 1, 2, 2, 2, 0, 0, 2, 1])
# test([1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0])
# test([0, 0, 0, 0, 0, 1, 0, 0, 1, 2, 0, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ])
# test([0] * 21 + [2] + [0] * 21)
# exit()

def solve(n, aaa):
    # シェルピンスキーの三角形
    if '2' not in aaa:
        factor = '3'
        effect = 2
    else:
        factor = '2'
        effect = 1
    # print(factor, effect)

    try_list = []
    m = n - 1
    while m:
        l = 1 << (m.bit_length() - 1)
        m ^= l
        try_list.append((l, m))
    # print(try_list)

    ans = 0
    for i, a in enumerate(aaa):
        if a == factor:
            for l, m in try_list:
                if i >= l:
                    i -= l
                if i == 0:
                    ans ^= effect
                    break
                elif i > m:
                    break
    return ans


n = int(input())
aaa = input()
print(solve(n, aaa))

Buggy python submission (verdict: Runtime Error):
from operator import mul


def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        print(' ' * i, *a)


def first(aaa):
    aaa = list(map(int, aaa))
    aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return aaa


def last(aaa):
    for i in range(len(aaa) - 1):
        aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return aaa[0]


def prepare():
    # for v in product([0, 1, 2], repeat=10):
    ret = [0] * (3 ** 10)
    for i in range(3 ** 10):
        v = i
        v, m1 = divmod(v, 3)
        tmp = []
        for _ in range(9):
            v, m2 = divmod(v, 3)
            tmp.append(abs(m1 - m2))
            m1 = m2
        tmp.reverse()
        for _ in range(8):
            tmp = [abs(a1 - a0) for a0, a1 in zip(tmp, tmp[1:])]
        ret[i] = tmp[0]
    return ret


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 3, 1, 3, 1, 3, 1, 3, 1, 3])

n = int(input())
aaa = input()
aaa = first(aaa)
ppp = prepare()
pow3 = [3 ** (9 - i) for i in range(10)]
while len(aaa) >= 10:
    aaa = [ppp[sum(map(mul, zip(aaa[i:i + 10], pow3)))] for i in range(len(aaa) - 9)]
ans = last(aaa)
print(ans)


Fixed submission:
def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        # print(' ' * i, *a)
        print(*a)


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 2, 0, 1, 2, 2, 2, 0, 0, 2, 1])
# test([1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0])
# test([0, 0, 0, 0, 0, 1, 0, 0, 1, 2, 0, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ])
# test([0] * 21 + [2] + [0] * 21)
# exit()

def solve(n, aaa):
    # シェルピンスキーの三角形
    if '2' not in aaa:
        factor = '3'
        effect = 2
    else:
        factor = '2'
        effect = 1
    # print(factor, effect)

    try_list = []
    m = n - 1
    while m:
        l = 1 << (m.bit_length() - 1)
        m ^= l
        try_list.append((l, m))
    # print(try_list)

    ans = 0
    for i, a in enumerate(aaa):
        if a == factor:
            for l, m in try_list:
                if i >= l:
                    i -= l
                if i == 0:
                    ans ^= effect
                    break
                elif i > m:
                    break
    return ans


n = int(input())
aaa = input()
print(solve(n, aaa))

Buggy python submission (verdict: Time Limit Exceeded):
def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        print(' ' * i, *a)


def first(aaa):
    aaa = list(map(int, aaa))
    aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return ''.join(map(str, aaa))


def last(aaa):
    aaa = list(map(int, aaa))
    for i in range(len(aaa) - 1):
        aaa = [abs(a1 - a0) for a0, a1 in zip(aaa, aaa[1:])]
    return aaa[0]


def prepare():
    # for v in product([0, 1, 2], repeat=10):
    ret = [0] * (3 ** 10)
    for i in range(3 ** 10):
        v = i
        v, m1 = divmod(v, 3)
        tmp = []
        for _ in range(9):
            v, m2 = divmod(v, 3)
            tmp.append(abs(m1 - m2))
            m1 = m2
        tmp.reverse()
        for _ in range(8):
            tmp = [abs(a1 - a0) for a0, a1 in zip(tmp, tmp[1:])]
        ret[i] = str(tmp[0])
    return ret


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 3, 1, 3, 1, 3, 1, 3, 1, 3])

n = int(input())
aaa = input()
aaa = first(aaa)
ppp = prepare()
while len(aaa) >= 10:
    aaa = ''.join(ppp[int(aaa[i:i + 10], 3)] for i in range(len(aaa) - 9))
ans = last(aaa)
print(ans)


Fixed submission:
def test(a):
    print(*a)
    for i in range(len(a) - 1):
        a = [abs(a1 - a0) for a0, a1 in zip(a, a[1:])]
        # print(' ' * i, *a)
        print(*a)


# test([2, 3, 1, 1, 3, 1, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 2, 2, 3, 1, 2])
# test([2, 3, 1, 1, 3, 3, 2, 3, 1, 2])
# test([1, 2, 0, 1, 2, 2, 2, 0, 0, 2, 1])
# test([1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0])
# test([0, 0, 0, 0, 0, 1, 0, 0, 1, 2, 0, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ])
# test([0] * 21 + [2] + [0] * 21)
# exit()

def solve(n, aaa):
    # シェルピンスキーの三角形
    if '2' not in aaa:
        factor = '3'
        effect = 2
    else:
        factor = '2'
        effect = 1
    # print(factor, effect)

    try_list = []
    m = n - 1
    while m:
        l = 1 << (m.bit_length() - 1)
        m ^= l
        try_list.append((l, m))
    # print(try_list)

    ans = 0
    for i, a in enumerate(aaa):
        if a == factor:
            for l, m in try_list:
                if i >= l:
                    i -= l
                if i == 0:
                    ans ^= effect
                    break
                elif i > m:
                    break
    return ans


n = int(input())
aaa = input()
print(solve(n, aaa))