#include<bits/stdc++.h> #define fi first #define se second #define ll long long using namespace std; int n;ll L,a[705]; namespace sub0{ void xuly(){ ll dem=a[n+1],d=0; for (ll i=n+2;i<=2*n+1;i++){ d++; ll z=L/d;dem+=min(a[i],z); // cout<<a[i]<<" "<<z*d<<endl; L-=(min(a[i],z)*d); } cout<<dem; } } int main(){ // if (fopen("thu.inp","r")){ // freopen("thu.inp","r",stdin); // freopen("thu.out","w",stdout); // } ios_base::sync_with_stdio(0); cin.tie(0);cout.tie(0); cin>>n;cin>>L; for (int i=1;i<=2*n+1;i++) cin>>a[i]; bool kt=true; for (int i=1;i<=n;i++) if (a[i]!=0) kt=false; if (kt==true) return sub0::xuly(),0; }