#include<cstdio>
#include<iostream>
#include<algorithm>
#include<queue>
#include<cstring>
using namespace std;
const int maxn=250000+10;
typedef long long LL;
LL n,ans,temp;
LL x[maxn],y[maxn];
priority_queue<LL>que;
int main(){
	freopen("wing.in","r",stdin);
	freopen("wing.out","w",stdout);
	scanf("%lld",&n);
	for(int i=1;i<=n;i++){
		scanf("%lld",&x[i]);	
	}
	for(int i=1;i<=n;i++){
		scanf("%lld",&y[i]);	
	}
	for(int i=1;i<=n;i++){
		temp+=x[i];
		if(temp>=y[i]){
			temp-=y[i];
			ans++;
			que.push(y[i]);
		}
		else {
			if(!que.empty()){
				int t=que.top();//printf("%lld",t);
				if(t>y[i]){
					temp-=y[i];temp+=t;
					que.pop();
					que.push(y[i]);
				}
			}
		}
	}//printf("%lld",temp);
	printf("%lld",ans);
	return 0;
}