#include <iostream>
#include <fstream>
using namespace std;
ofstream fo("ssm.out");
ifstream fi("ssm.in");
long long a[6000007], b[6000007], s = 0, i, j, n, maxim = 0;
int main()
{
  fi >> n;
  for (i = 1; i <= n; i++)
    fi >> a[i];
  for (i = 1; i <= n; i++)
  { s+=a[i];
    if (s < 0) s = 0;
      else b[i] = s;
  }
  for (i = 1; i <= n; i++)
    if (b[i] > maxim ) maxim = b[i];
          fo << maxim;
  return 0;
}