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

int tempo_massimo(int N, int a[], int b[])
{
    vector<int> dp(N);
    dp[0] = max(a[0], b[0]);
    for (int i=1;i<N;i++) {
        if (i==1) dp[i] = max(dp[i-1] + a[i], b[i]);
        else dp[i] = max(dp[i-1]+a[i], dp[i-2]+b[i]);
    }
    return dp[N-1];
}