Buggy python submission (verdict: Runtime Error):
import numpy as np
from numba import njit

@njit
def solve(A, F, K):
    lo = 0
    hi = 10 ** 12
    while lo < hi:
        mid = (lo + hi) // 2
        total_train = 0
        for i in range(A.shape[0]):
            need = A[i] - mid // F[i]
            total_train += need if need > 0 else 0
        if total_train <= K:
            hi = mid
        else:
            lo = mid + 1
    return lo

stdin = np.fromstring(open(0).read(), dtype=np.int64, sep=' ')
N, K = stdin[:2]
A = stdin[2: 2 + N]
F = stdin[2 + N:]
print(solve(np.sort(A)[::-1], np.sort(F), K))

Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

start = -1
end = A[-1] * F[0]

def check(now):
    cnt = 0
    for a, f in zip(A, F):
        # cnt += max(0, a-now//f)
        eatable = now//f
        if eatable < a:
            cnt += a - eatable
    return cnt <= K
    # if cnt > K:
    #     return False
    # return True

while end > start + 1:
    now = (start + end) // 2
    if check(now):
        end = now
    else:
        start = now

print(end)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

start = -1
end = A[-1] * F[0]

def check(now):
    cnt = 0
    for a, f in zip(A, F):
        cnt += max(0, a-now//f)
        # eatable = now//f
        # if eatable < a:
        #     cnt += a - eatable
    return cnt <= K
    # if cnt > K:
    #     return False
    # return True

while end > start + 1:
    now = (start + end) // 2
    if check(now):
        end = now
    else:
        start = now

print(end)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

start = -1
end = A[-1] * F[0]

def check(now):
    cnt = 0
    for i in range(N):
        if A[i] * F[i] > now:
            cnt += (A[i]*F[i] - now + F[i] - 1) // F[i]
    if cnt > K:
        return False
    return True

while end > start + 1:
    now = (start + end) // 2
    if check(now):
        end = now
    else:
        start = now

print(end)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = -1
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

print(end)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    import heapq
    N, K = map(int, input().split())
    A = list(map(int, input().split()))
    if sum(A) <= K:
        print(0)
        return

    F = list(map(int, input().split()))

    A.sort()
    F.sort(reverse=True)
    q = []
    for i in range(N):
        heapq.heappush(q, (-(A[i]*F[i]), A[i], F[i]))

    k = K
    while k > 0:
        p, a, f = heapq.heappop(q)
        if p < 0:
            nextp = q[0][0]
            tmp = min(min(max((nextp-p+f-1)//f, 1), k), a)
            heapq.heappush(q, ((-(a-tmp)*f), a-tmp, f))
            k -= tmp
        else:
            break

    p, a, f = heapq.heappop(q)
    print(-p)
    return

main()

Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    import heapq
    N, K = map(int, input().split())
    A = list(map(int, input().split()))
    if sum(A) <= K:
        print(0)
        return

    F = list(map(int, input().split()))

    A.sort()
    F.sort(reverse=True)
    q = []
    for i in range(N):
        heapq.heappush(q, (-(A[i]*F[i]), A[i], F[i]))

    for k in range(K):
        p, a, f = heapq.heappop(q)
        if p < 0:
            heapq.heappush(q, ((-(a-1)*f), a-1, f))
        else:
            break

    p, a, f = heapq.heappop(q)
    print(-p)
    return

main()

Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)

Buggy python submission (verdict: Time Limit Exceeded):
import heapq
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))

A.sort()
F.sort(reverse=True)
q = []
for i in range(N):
    heapq.heappush(q, (-(A[i]*F[i]), A[i], F[i]))

for k in range(K):
    p, a, f = heapq.heappop(q)
    if p < 0:
        heapq.heappush(q, ((-(a-1)*f), a-1, f))
    else:
        break

p, a, f = heapq.heappop(q)
print(-p)


Fixed submission:
N, K = map(int, input().split())
A = list(map(int, input().split()))
F = list(map(int, input().split()))
A.sort()
F.sort(reverse=True)

q = [0] * N
start = 0
end = 0
for i in range(N):
    q[i] = A[i] * F[i]
    end = max(end, q[i])

def check(now, K):
    cnt = 0
    for i in range(N):
        if q[i] - now > 0:
            cnt += (q[i] - now + F[i] - 1) // F[i]
            if cnt > K:
                return False
    return True

now = end // 2
while end > start + 1:
    if check(now, K):
        end = now
    else:
        start = now
    now = (start + end) // 2

if check(start, K):
    print(start)
else:
    print(end)