Buggy python submission (verdict: Time Limit Exceeded):
import sys
sys.setrecursionlimit(100000000)


def main():
    N, K, C = map(int, input().split())
    S = input()

    end = len(S)
    fullbit = (1 << end) - 1

    ans = [None]

    def search(i, bit, cnt):
        if cnt == 0:
            if ans[0] is None:
                ans[0] = fullbit
            ans[0] &= bit
            return
        if i >= end:
            return
        search(i + 1, bit, cnt)
        if S[i] == 'x':
            return
        search(i + C + 1, bit | (1 << i), cnt - 1)

    search(0, 0, K)
    if ans[0] is not None:
        for i in range(N):
            if (ans[0] & (1 << i)) != 0:
                print(i + 1)


main()


Fixed submission:
import sys
sys.setrecursionlimit(100000000)


def main():
    N, K, C = map(int, input().split())
    S = input()

    def forward(k):
        i = 0
        day = 0
        days = [-1] * k
        l = len(S)
        while day < k and i < l:
            while S[i] == 'x':
                i += 1
                if i >= l:
                    return None
            days[day] = i
            day += 1
            i += 1 + C
        if day < k:
            return None
        return days

    def backward(k):
        day = k
        days = [-1] * k
        l = len(S)
        i = l - 1
        while day > 0 and i >= 0:
            while S[i] == 'x':
                i -= 1
                if i < 0:
                    return None
            day -= 1
            days[day] = i
            i -= (1 + C)
        if day > 0:
            return None
        return days

    left = forward(K)
    if left is None:
        return

    right = backward(K)
    for i, j in zip(left, right):
        if i == j:
            print(i + 1)

main()

Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(10000)


def main():
    N, K, C = map(int, input().split())
    S = input()

    end = len(S)
    fullbit = (1 << end) - 1

    ans = [None]

    def search(i, bit, cnt):
        if cnt == K:
            if ans[0] is None:
                ans[0] = fullbit
            ans[0] &= bit
            return
        if i >= end:
            return
        search(i + 1, bit, cnt)
        if S[i] == 'x':
            return
        search(i + C + 1, bit | (1 << i), cnt + 1)

    search(0, 0, 0)
    if ans[0] is not None:
        for i in range(N):
            if (ans[0] & (1 << i)) != 0:
                print(i + 1)


main()


Fixed submission:
import sys
sys.setrecursionlimit(100000000)


def main():
    N, K, C = map(int, input().split())
    S = input()

    def forward(k):
        i = 0
        day = 0
        days = [-1] * k
        l = len(S)
        while day < k and i < l:
            while S[i] == 'x':
                i += 1
                if i >= l:
                    return None
            days[day] = i
            day += 1
            i += 1 + C
        if day < k:
            return None
        return days

    def backward(k):
        day = k
        days = [-1] * k
        l = len(S)
        i = l - 1
        while day > 0 and i >= 0:
            while S[i] == 'x':
                i -= 1
                if i < 0:
                    return None
            day -= 1
            days[day] = i
            i -= (1 + C)
        if day > 0:
            return None
        return days

    left = forward(K)
    if left is None:
        return

    right = backward(K)
    for i, j in zip(left, right):
        if i == j:
            print(i + 1)

main()

Buggy python submission (verdict: Runtime Error):
def main():
    N, K, C = map(int, input().split())
    S = input()

    end = len(S)
    fullbit = (1 << end) - 1

    ans = [None]

    def search(i, bit, cnt):
        if cnt == K:
            if ans[0] is None:
                ans[0] = fullbit
            ans[0] &= bit
            return
        if i >= end:
            return
        search(i + 1, bit, cnt)
        if S[i] == 'x':
            return
        search(i + C + 1, bit | (1 << i), cnt + 1)

    bit = search(0, 0, 0)
    for i in range(N):
        if (ans[0] & (1 << i)) != 0:
            print(i + 1)


main()


Fixed submission:
import sys
sys.setrecursionlimit(100000000)


def main():
    N, K, C = map(int, input().split())
    S = input()

    def forward(k):
        i = 0
        day = 0
        days = [-1] * k
        l = len(S)
        while day < k and i < l:
            while S[i] == 'x':
                i += 1
                if i >= l:
                    return None
            days[day] = i
            day += 1
            i += 1 + C
        if day < k:
            return None
        return days

    def backward(k):
        day = k
        days = [-1] * k
        l = len(S)
        i = l - 1
        while day > 0 and i >= 0:
            while S[i] == 'x':
                i -= 1
                if i < 0:
                    return None
            day -= 1
            days[day] = i
            i -= (1 + C)
        if day > 0:
            return None
        return days

    left = forward(K)
    if left is None:
        return

    right = backward(K)
    for i, j in zip(left, right):
        if i == j:
            print(i + 1)

main()