#include <bits/stdc++.h>   using namespace std;   int main() {     int n, k, i, teo = 0, s = 0, a[100001], t[100001];     cin >> n >> k;     for (i = 1; i <= n; i++) cin >> a[i];     for (i = 1; i <= n; i++) {       cin >> t[i];       if (t[i] == 1) {         teo = teo + a[i];         a[i] = 0;       }       a[i] = a[i] + a[i - 1];     }     for (i = k; i <= n; i++) s = max(s, a[i] - a[i - k]);     cout << teo + s;   }   