import java.util.*;
import java.lang.*;
import java.io.*;
public class Main
{
        public static void  solve(int a[],int n)
        {
                HashMap<Integer,Integer> map=new HashMap<>();

                int sum=0;
                int ans=0;

                for(int i=0;i<n;i++)
                {
                       sum+=a[i];

                        if(sum==0)
                                ans=i+1;

                        if(map.containsKey(sum))
                                ans=Math.max(ans,i-map.get(sum));
                        else
                                map.put(sum,i);
                }

                System.out.println(ans);
        }

	public static void main (String[] args) throws java.lang.Exception
	{
		//your code here
                Scanner sc=new Scanner(System.in);

                int n=sc.nextInt();
                int a[]=new int[n];

                for(int i=0;i<n;i++)
                        a[i]=sc.nextInt();

               solve(a,n);
	}
}