#include <bits/stdc++.h>
using namespace std;
 
int main() {
	int n;
	cin>>n;
	vector<int> a(n+1);
	vector<int> b(n+1);
	for(int i=1;i<=n;i++){
		int elementA;
		cin>>elementA;
		a[i]=elementA;
	}
	for(int i=1;i<=n;i++){
		int elementB;
		cin>>elementB;
		b[i]=elementB;
	}
	vector<int> dp(n+1, 0);
	dp[1]=max(a[1], b[1]);
	dp[2]=max(dp[1], max(a[2], b[2]));
	for(int i=3;i<=n;i++){
		dp[i] = max(dp[i-1], max(a[i] + dp[i-2], b[i] + dp[i-2]));
	}
	cout<<dp[n];
	return 0;
}

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NQoyIDMgNCAtOCAyCi01IDggMyAxIC00

5
2 3 4 -8 2
-5 8 3 1 -4