func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mxn = 2e5 + 5;   void solve() {     long long n, k;     cin >> n >> k;     long long arr[n];     for (long long int i = 0; i < n; i++) cin >> arr[i];     long long a;     cin >> a;     long long c[n];     for (long long int i = 0; i < n; i++) cin >> c[i];     long long ans = 0, f = 0;     priority_queue<long long, vector<long long>, greater<long long> > pq;     for (long long int i = 0; i < n; i++) {       if (arr[i] <= k) {         pq.push(c[i]);       } else if (arr[i] > k) {         pq.push(c[i]);         long long gap = arr[i] - k;         gap = ceil(gap * 1.0 / a);         if (pq.size() >= gap) {           while (gap--) {             ans += pq.top();             pq.pop();             k += a;           }         } else {           f = 1;           break;         }       }     }     if (f)       cout << -1 <<   n ;     else       cout << ans <<   n ;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     long long t = 1;     while (t--) {       solve();     }     return 0;   }   