#include<bits/stdc++.h>
#define MAXN 100007
using namespace std;
struct rect{
long long minx,maxx;
long long miny,maxy;
inline friend rect operator + (rect fr,rect sc){
return {max(fr.minx,sc.minx),min(fr.maxx,sc.maxx),max(fr.miny,sc.miny),min(fr.maxy,sc.maxy)};
}
};
const long long inf=1e15;
int n,len[MAXN],d[MAXN],c;
long long pos[MAXN];
bool ok(long long fix){
rect s={-inf,inf,-inf,inf},curr;
for(int i=1;i<=n;i++){
for(int f=i+1;f<=n;f++){
if(pos[f]-pos[i]+d[i]+d[f]<=fix)continue;
long long w=fix-d[i]-d[f]-c;
if(w<0)return false;
curr={pos[f]-pos[i]-w,pos[f]-pos[i]+w,pos[i]+pos[f]-w,pos[i]+pos[f]+w};
s=s+curr;
}
}
for(int i=1;i<=n;i++){
for(int f=i+1;f<=n;f++){
if(pos[f]-pos[i]>=s.minx and pos[f]-pos[i]<=s.maxx and pos[f]+pos[i]>=s.miny and pos[f]+pos[i]<=s.maxy)return true;
}
}
return false;
}
long long find_shortcut(int N,vector<int> L,vector<int> D, int C){
n=N; c=C;
for(int i=1;i<=n-1;i++){
len[i]=L[i-1];
}
for(int i=2;i<=n;i++){
pos[i]=pos[i-1]+len[i-1];
}
for(int i=1;i<=n;i++){
d[i]=D[i-1];
}
long long l=0,r=inf,tt;
while(l+1<r){
tt=(l+r)/2;
if(ok(tt)){
r=tt;
}else{
l=tt;
}
}
return r;
}
/*int main(){
//cout<<find_shortcut(9, {10, 10, 10, 10, 10, 10, 10, 10},{20, 0, 30, 0, 0, 40, 0, 40, 0}, 30)<<"\n";
//cout<<find_shortcut(4, {2, 2, 2},{1, 10, 10, 1}, 1)<<"\n";
cout<<find_shortcut(3, {1, 1},{1, 1, 1}, 3)<<"\n";
return 0;
}*/
