#include <iostream>
using namespace std;
long long int t, suma=0, suma2, maks;
int liczba;
int main()
{
cin >> t;
for(int k = 0; k<t; k++)
{
cin >> liczba;
suma+=liczba;
suma2+=liczba;
if(suma>=maks&&suma>=suma2)maks=suma;
else if(suma2>maks)
{
maks=suma2;
}
else if(suma>suma2);
else suma = 0;
}
cout << maks <<endl;
return 0;
}
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