#include <iostream>
#include <fstream>

using namespace std;

long long a[6000001],b[6000001],minim,maxim;
int n;
int main()
{
    freopen("ssm.in","r",stdin);
    freopen("ssm.out","w",stdout);
    int p = 0;
    scanf("%d",&n);
    for (int i=1; i<=n; i++) scanf("%I64d",&a[i]);

    for (int i=1; i<=n; i++){
        b[i]+=(b[i-1]+a[i]);
        if(b[i]-minim>maxim) maxim=b[i]-minim;
        if(b[i]<minim) minim=b[i];
    }
    printf("%I64d",maxim);
}