#pragma GCC optimize("O3") #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #pragma GCC target("avx,avx2") #include <bits/stdc++.h> #define INF 1000000001LL #define LNF 1000000000000000001LL #define MOD 998244353LL #define MAX 2001 #define long long long #define all(x) x.begin(),x.end() using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(0); long n,h; cin >> n >> h; vector<int> brr(n); for(int i = 0; i<n; i++) cin >> brr[i]; vector<long> arr(n); vector<long> hap(n+1); for(int i = 0; i<n; i++) { cin >> arr[i]; hap[i+1] = hap[i]+arr[i]; } long res = 0; long right = 0; long cur = 0; long sum = 0; for(int i = 0; i<n; i++) { while(cur<=h && right <= n) { res = max(res,sum); if(right == n) break; cur+=(right-i+1)*arr[right]; sum+=brr[right]; right++; } cur-=hap[right]-hap[i]; sum-=brr[i]; } cout << res << endl; return 0; }