/*
*/

//#pragma comment(linker, "/STACK:16777216")
#define _CRT_SECURE_NO_WARNINGS

#include <fstream>
#include <iostream>
#include <string>
#include <complex>
#include <math.h>
#include <set>
#include <vector>
#include <map>
#include <queue>
#include <stdio.h>
#include <stack>
#include <algorithm>
#include <list>
#include <ctime>
#include <memory.h>
#include <assert.h>

#define y0 sdkfaslhagaklsldk
#define y1 aasdfasdfasdf
#define yn askfhwqriuperikldjk
#define j1 assdgsdgasghsf
#define tm sdfjahlfasfh
#define lr asgasgash
#define norm asdfasdgasdgsd

#define eps 1e-9
#define M_PI 3.141592653589793
#define bs 1000000007
#define bsize 256

using namespace std;

const int INF = 1e9;
const int N = 500031;

vector<pair<long long, long long> >v;
int n;
long long a[N], b[N];
long long ans;

int main(){
	//freopen("fabro.in","r",stdin);
	//freopen("fabro.out","w",stdout);
	//freopen("F:/in.txt", "r", stdin);
	//freopen("F:/output.txt", "w", stdout);
	ios_base::sync_with_stdio(0);
	//cin.tie(0);

	cin >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i];
	for (int i = 1; i <= n; i++)
		cin >> b[i];
	for (int i = 1; i <= n; i++)
		a[i] += a[i - 1];
	for (int i = 1; i <= n; i++)
		b[i] += b[i - 1];

	for (int i = 0; i <= n; i++)
	{
		v.push_back(make_pair(a[i] - b[i], i));
	}

	sort(v.begin(), v.end());

	int block = 0;

	for (int i = 0; i < v.size(); i++)
	{
		if (i>0 && v[i].first != v[i - 1].first)
			block = i;

		ans = max(v[i].second - v[block].second,ans);
	}

	cout << ans << endl;

	cin.get(); cin.get();
	return 0;
}