#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
vector<double> num;
const double eps = 1e-6;
double a[1015],b[1015];
int n,k;
bool judge(double mid)
{
num.clear();
for (int i = 0; i < n; i++)
{
num.push_back(a[i]-b[i]*mid);
}
sort(num.begin(),num.end());
double res = 0;
for (int i = k; i < n; i++)
{
res += num[i];
}
if( res > 0 ) return true;
else return false;
}
int main()
{
while( cin >> n >> k )
{
if( n == 0 && k == 0 ) break;
for (int i = 0; i < n; i++) cin >> a[i];
for (int i = 0; i < n; i++) cin >> b[i];
double l = 0, r = 1e18;
double ans = 0;
while( r - l > eps )
{
double mid = ( r + l ) / 2;
if( judge(mid) )
{
ans = mid;
l = mid;
}else r = mid;
}
ans *= 100;
int res = floor(ans+0.5);
cout << res << endl;
}
return 0;
}
