stocks.cpp

// NOTE: it is recommended to use this even if you don't understand the following code.

#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

// input data
long long N;
vector<long long> V, S;

int main() {
//  uncomment the following lines if you want to read/write from files
	ifstream cin("input.txt");
	ofstream cout("output.txt");

    cin >> N;
    V.resize(N);
    S.resize(N);
    for (long long i=0; i<N; i++)
        cin >> V[i];
    for (long long i=0; i<N; i++)
        cin >> S[i];

    // insert your code here
    long long sum = 0;
    
    for (long long i=0; i<N; i++) {
    	bool good = false, nuovo = true;
    	long long temp;
    	if (i==0 && S[0] == 1) {
    		temp = V[0];
    		if (N>=2) {
    			i++;
			}
			good = true;
		} else {
			temp = 0;
		}
		
		while (S[i] == 1) {
			if (V[i] >= V[i-1] || nuovo) {
				temp += V[i];
				good = true;
				nuovo = false;
				if (i < N-1) {
					i++;
				} else {
					break;
				}
			} else {
				i--;
				break;
			}
		}
		
		if (temp > sum && good) {
			sum = temp;
		}
	}
	
    cout << sum << endl; // print the result
    return 0;
}