#include <bits/stdc++.h>
using namespace std;

/*
scanf("%d",&x);
printf("%d\n",x);
*/

const int NMAX=100005;

int n;
long long a[NMAX],b[NMAX],suma[NMAX],sumb[NMAX];
map<long long , int > M;

int main() 
{
	int i,j,ans=0;
	long long aux;
	//freopen("date1.txt","r",stdin);
	//freopen("date2.txt","w",stdout);
	scanf("%d",&n);
	for (i=1;i<=n;i++) 
		{
			scanf("%d",&a[i]);
			suma[i]+=suma[i-1]+a[i];
	}
	for (i=1;i<=n;i++) 
		{
			scanf("%d",&b[i]);
			sumb[i]+=sumb[i-1]+b[i];
	}
	
	M[0]=0;
	for (i=1;i<=n;i++)
	{
		aux=suma[i]-sumb[i];
		if (M.find(aux)!=M.end()) ans=max(ans,i-M[aux]);
		M[aux]=i;
	}
	printf("%d",ans);
	return 0;
}