#include <iostream.h>
#include <stdio.h>

int sum,s[1000],n, j,maxim; 
int main()
{
    freopen("ssm.in ", "r", stdin);
   freopen("ssm.out", "w", stdout);
    cin>>n;
    for (int i=1; i<n; i++)
    cin>>s[i];
    for (int k=1; k<n; k++)
    {sum=0;
    for (int j=k;j<=n; j++) 
    sum = sum + s[j];
    if (sum > maxim);
    sum=maxim;
    }
    cout<<maxim;
    
    return 0; 
}