#pragma GCC optimize("Ofast,unroll-loops")
#include<bits/stdc++.h>
#define int   long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP     ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task2 "ftree"
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime   cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
#define getchar_unlocked getchar
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l,int r)
{
    return uniform_int_distribution<int>(l,r)(rd);
}
inline int scan()
{
    char c = getchar_unlocked();
    int x = 0;
    while (c < '0' || c > '9')
    {
        c = getchar_unlocked();
    }
    while (c >= '0' && c <= '9')
    {
        x = (x << 1) + (x << 3) + c - '0';
        c = getchar_unlocked();
    }
    return x;
}
void phongbeo();
const int inf = 1e16;
const ll mod2 = 1e9+7;
const int  mod1 = 998244353;
const ll base=67;
int add(int x,int y)
{
    if(x+y>=mod2) x-=mod2;
    if(x+y<0)x+=mod2;
    return x+y;
}
struct icd
{
    long double a;
    int b;
};
struct ib
{
    int a;
    int b;
};
struct ic
{
    int a,b,c;
};
struct id
{
    int a, b, c, d;
};
struct ie
{
    int a, b, c, d, e;

};
int  n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
int  i, s10, s12,k1,k2,k3,s11,lim,w,l,r ;
int kk;
int el = 19;
main()
{
    if(fopen(task2".inp","r"))
    {
        fin(task2);
        fou(task2);
    }
    if(fopen(task".inp","r"))
    {
        fin(task);
        fou(task);
    }
    NHP
    /// cin>>s1;
    //modwwe
    phongbeo(),down
    // checktime
}
int a[500007];
int b[500007];
int t[500007];
int suff[500007];
int pre[500007];
void phongbeo()
{
    cin>>n;
    for(int i=1; i<=n; i++)
        cin>>a[i];
    for(int i=1; i<=n; i++)
        cin>>b[i],b[i]+=b[i-1];
    for(int i=1; i<=n; i++)
    {
        t[i]=a[i]-b[i-1];
    }
    suff[n+1]=-1e12;
    pre[0]=-1e12;
    for(int i=n; i>=1; --i)
        suff[i]=max(suff[i+1],t[i]);
    for(int i=1; i<=n; i++)
        pre[i]=max(pre[i-1],t[i]);
    s4=1e9+1;
    for(int i=1; i<=n; i++)
    {
        s5=max({pre[i-1]-b[n]+b[i-1],suff[i]+b[i-1],0ll});
        s4=min(s4,s5);
    }
    cout<<s4;
}