#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

struct NR
{
	int val, i;
};

bool comp(NR A, NR B)
{
	if(A.val==B.val)
		return A.i<B.i;
	return A.val<B.val;
}

vector<NR> vec;
int s1[100005], s2[100005];
int a, b, i, n, minim, maxim;

int main()
{
	cin>>n;
	for(i=1; i<=n; i++)
	{
		cin>>a;
		s1[i]=s1[i-1]+a;
	}
	for(i=1; i<=n; i++)
	{
		cin>>b;
		s2[i]=s2[i-1]+b;
	}
	for(i=1; i<=n; i++)
	{
		NR x;
		x.val=s1[i-1]-s2[i-1];
		x.i=i-1;
		vec.push_back(x);
	}
	sort(vec.begin(), vec.begin()+vec.size(), comp);
	for(i=n; i>=1; i--)
	{
		//if(s1[i]-s2[i])
		int val=s1[i]-s2[i];
		int st=0;
		int dr=vec.size()-1;
		minim=9999999;
		while(st<=dr)
		{
			int mid=(st+dr)/2;
			if(vec[mid].val==val)
			{
				if(vec[mid].i<minim)
				{
					minim=vec[mid].i;
					dr=mid-1;
				}
			}
			if(vec[mid].val<val)
			{
				st=mid+1;
			}
			if(vec[mid].val>val)
			{
				dr=mid-1;
			}
		}
		if(i-minim>maxim)
			maxim=i-minim;
	}	
	cout<<maxim;
}