#include <bits/stdc++.h>
using namespace std;
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define sp " "
#define endl "\n"
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 500005
#define int long long
const int INF = 1e9 + 7;
int x[N], l[N];
int32_t main(){
//fileio();
fastio();
int n;
cin>>n;
for (int i = 1; i <= n; i++){
cin>>x[i];
}
for (int i = 1; i <= n; i++){
cin>>l[i];
}
vector<int> v(n, 0);
iota(v.begin(), v.end(), 1);
sort(v.begin(), v.end(), [&](int a, int b){
if (x[a] == x[b]) return l[a] < l[b];
return x[a] < x[b];
});
int sum = 0;
int ans = 0;
multiset<pii> maks;
for (auto i : v){
if (sum <= l[i]){
sum += x[i];
ans++;
maks.insert({l[i] + x[i], x[i]});
continue;
}
int tmp = sum;
auto it = maks.rbegin();
while(it != maks.rend() && it->st >= tmp + x[i]){
tmp -= it->nd;
it++;
if (tmp <= l[i]){
sum += x[i];
ans++;
maks.insert({l[i] + x[i], x[i]});
break;
}
}
}
//cout<<endl;
cout<<ans<<endl;
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
