#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll

const int N = 1e3+10,mo = 1e9+7;

int a[N],b[N];
int pre[N],suf[N];
int dp1[N],dp2[N];
inline void solve(){
    int n;
    cin>>n;
    for(int i=1;i<=n;++i) cin>>a[i],pre[i]=pre[i-1]+a[i];
    for(int i=1;i<=n;++i) cin>>b[i];
    for(int i=n;i>=1;--i) suf[i]=suf[i+1]+a[i];
    dp1[n+1]=mo,dp2[0]=mo,dp1[n]=a[n]+b[n];
    for(int i=n-1;i>=1;--i){
        dp1[i]=max(min(dp1[i+1],dp1[i+2]),suf[i])+b[i];
    }
    for(int i=2;i<=n;++i){
        dp2[i]=max(min(dp2[i+1],dp2[i+2]),pre[i])+b[i];
    }
    cout<<min(dp1[1],dp2[n])<<endl;
}



signed main(){
    ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
    int WTN666=1;//cin>>WTN666;
    while(WTN666--){
        solve();
    }
}