#include <iostream>
using namespace std;
int f1[155], f2[155];
int main() {
int n, m, k, r;
cin >> n >> m >> k >> r;
int a[n], t[m], s[m];
for (int i=0; i<n; ++i)
cin >> a[i];
for (int i=0; i<m; ++i)
cin >> t[i];
for (int i=0; i<m; ++i)
cin >> s[i];
for (int i=0; i<m; ++i)
for (int j=r; j>=t[i]; --j)
f1[j] = max(f1[j], f1[j-t[i]]+s[i]);
for (int i=0; i<=r; ++i)
if (f1[i]>=k) {
r -= i;
break;
}
for (int i=0; i<n; ++i)
for (int j=r; j>=a[i]; --j)
f2[j] = max(f2[j], f2[j-a[i]]+1);
cout << f2[r] << endl;
return 0;
}
