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

int tempo_massimo(int N, int a[], int b[]){
	long long s = 0;
	vector<int> somme;
	vector <bool> preso;
	somme[0] = 0;
	b[N] = 0;
	for(int i = 0; i < N; i++){
		preso.push_back(false);
		somme[i + 1] = b[i] + b[i+1];
	}
	for(int i = 0; i < N; i++){
		if(somme[i] < b[i] && b[i] < b[i +1] && b[i] < a[i] && preso[i] == false){
			preso[i] = true;
			s += b[i];
		}else if(preso[i] == false) s+= a[i];
		else continue;
	}
	
    return s;
}