Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()


Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl
    from bisect import bisect_right as br

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        for i in a[:start_0]:
            if mid % i == 0:
                cnt += n - br(a, mid//i)
            else:
                cnt += n - br(a, mid//i + 0.5)
        for i in a[start_1:]:
            if mid % i == 0:
                cnt += bl(a, mid//i)
            else:
                cnt += bl(a, mid//i + 0.5)
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl
    from bisect import bisect_right as br

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        for i in a:
            if i < 0:
                if mid % i == 0:
                    cnt += n - br(a, mid//i)
                else:
                    cnt += n - br(a, mid//i + 0.5)
            elif i > 0:
                if mid % i == 0:
                    cnt += bl(a, mid//i)
                else:
                    cnt += bl(a, mid//i + 0.5)
            else:
                if mid > 0:
                    cnt += n
                else:
                    cnt += 0
        for i in a:
            if i*i < mid:
                cnt -= 1
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()


Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl
    from bisect import bisect_right as br

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        for i in a:
            if i < 0:
                if mid % i == 0:
                    cnt += n - br(a, mid//i)
                else:
                    cnt += n - br(a, mid//i + 0.5)
            elif i > 0:
                if mid % i == 0:
                    cnt += bl(a, mid//i)
                else:
                    cnt += bl(a, mid//i + 0.5)
            else:
                if mid > 0:
                    cnt += n
                else:
                    cnt += 0
        for i in a:
            if i*i < mid:
                cnt -= 1
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()


Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from bisect import bisect_left as bl
    from bisect import bisect_right as br

    def b_search(ok, ng, value):
        while abs(ok-ng) > 1:
            mid = (ok+ng)//2
            if value(mid):
                ok = mid
            else:
                ng = mid
        return ok

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    def check(x):
        cnt = 0
        for i in a:
            if i < 0:
                if x % i == 0:
                    cnt += n - br(a, x//i)
                else:
                    cnt += n - br(a, x//i + 0.1)
            elif i > 0:
                if x % i == 0:
                    cnt += bl(a, x//i)
                else:
                    cnt += bl(a, x//i + 0.1)
            else:
                if x > 0:
                    cnt += n
                else:
                    cnt += 0
        for i in a:
            if i*i < x:
                cnt -= 1
        return cnt//2 < k

    print(b_search(-inf, inf, check))


main()


Fixed submission:
def main():
    from bisect import bisect_left as bl

    n, k = map(int, input().split())
    a = list(map(int, input().split()))
    a.sort()

    inf = 10**18+1

    ok = -inf
    ng = inf
    start_0 = bl(a, 0)
    start_1 = bl(a, 1)

    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        cnt = 0
        if mid >= 0:
            now = 0
            if start_0 > 0:
                for i in a[start_0-1::-1]:
                    while now < n:
                        if i*a[now] >= mid:
                            now += 1
                        else:
                            break
                    cnt += n - now
            now = n
            for i in a[start_1:]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        else:
            now = 0
            for i in a[:start_0]:
                while now < n:
                    if i*a[now] >= mid:
                        now += 1
                    else:
                        break
                cnt += n - now
            now = n
            for i in a[n-1:start_1-1:-1]:
                while now > 0:
                    if i*a[now-1] >= mid:
                        now -= 1
                    else:
                        break
                cnt += now
        if mid > 0:
            cnt += n * (start_1 - start_0)
        cnt -= len([None for i in a if i*i < mid])
        if cnt//2 < k:
            ok = mid
        else:
            ng = mid
    print(ok)


main()