#include <algorithm>

#include <bitset>

#include <cctype>

#include <cerrno>

#include <clocale>

#include <cmath>

#include <complex>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <deque>

#include <exception>

#include <fstream>

#include <functional>

#include <limits>

#include <list>

#include <map>

#include <iomanip>

#include <ios>

#include <iosfwd>

#include <iostream>

#include <istream>

#include <ostream>

#include <queue>

#include <set>

#include <sstream>

#include <stdexcept>

#include <streambuf>

#include <string>

#include <utility>

#include <vector>

#include <cwchar>

#include <cwctype>

#include <stack>

#include <limits.h>

using namespace std;

#define MAXN 1010

const double eps = 1e-;

int i,n,k;

double l,r,mid,ans;

long long a[MAXN],b[MAXN];

double d[MAXN];

inline bool cmp(double a,double b)

{

        return a > b;

}

inline bool check()

{

        int i;

        double sum = ;

        sort(d+,d+n+,cmp);

        for (i = ; i <= n - k; i++) sum += d[i];

        return sum >= ;

}

int main()

{

        while (scanf("%d%d",&n,&k) != EOF && !(n ==  && k == ))

        {

                for (i = ; i <= n; i++) scanf("%lld",&a[i]);

                for (i = ; i <= n; i++) scanf("%lld",&b[i]);

                l = ; r = ;

                ans = ;

                while (r - l > eps)

                {

                        mid = (l + r) / 2.0;

                        for (i = ; i <= n; i++) d[i] = 1.0 * a[i] - mid * b[i];

                        if (check())

                        {

                                l = mid;

                                ans = mid;

                        } else r = mid;

                }

                printf("%lld\n",(long long)(ans*+0.5));

        }

        return ;

}