#include <bits/stdc++.h>
using namespace std;
 
typedef long long int ll;
 
int main() {
	ll n;
	cin >> n;
 
	vector<int> a(n, 0);
	vector<int> b(n, 0);
 
	// Reading array a
	for(int i=0; i<n; i++) {
		cin >> a[i];
	}
 
	// Reading array b
	for(int i=0; i<n; i++) {
		cin >> b[i];
	}
 
	vector<int> dp(n, 0);
 
	dp[0] = max(a[0], b[0]);
	dp[1] = max(dp[0], max(a[1], b[1]));
 
	for(int i=2; i<n; i++) {
		int x = dp[i-1];
		int y = b[i] + dp[i-2];
		int z = a[i] + dp[i-2];
 
		dp[i] = max(x, max(y,z));
		cout << i << " : " << dp[i] << endl;
	}
 
	cout << dp[n-1];
	return 0;
}

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NQoyIDMgNCAtOCAyCi01IDggMyAxIC00

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