#include<bits/stdc++.h>
using namespace std;


int tempo_massimo(int N, int A[], int B[])
{
	vector<int> super(N);
	vector<int> hyper(N);
	super[0] = A[0];
	hyper[0] = B[0];
	super[1] = super[0] + A[1];
	hyper[1] = B[1] + A[0];
	for(int i = 2; i < N; i++)
	{
		super[i] = max(super[i-1] + A[i], hyper[i-2] + A[i]);
		hyper[i] = max(super[i-1] + B[i], hyper[i-2] + B[i]);
	}
	return max(super[N-1], max(hyper[N-1], hyper[N-2]);
}