#include <iostream>
using namespace std;
int t[100007];
int main(){
int x;
cin >> x;
for (int i = 0; i < x; i++){
cin >> t[i];
}
int total = 0;
for (int i = 0; i < x; i++){
if(t[i] < 0 && (t[i]+t[i+1]) <= 0){
total = total;
}
//else if(t[i] < 0){
//total = total;
if ((total + t[i]) > (total + t[i] + t[i+1])){
total += t[i];
i++;
}
else if (t[i] > 0){
total += t[i];
}
}
cout << total << endl;
return 0;
}
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