#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
#define L(node) node * 2
#define R(node) node * 2 + 1
const int INF = 1e9 + 7;
int x[N], l[N], lazy[4 * N], tree[4 * N], ind[N];
int mini[4 * N];
void push(int node, int l, int r){
mini[node] += lazy[node];
if (l != r){
lazy[L(node)] += lazy[node];
lazy[R(node)] += lazy[node];
}
lazy[node] = 0;
}
void sett(int node, int l, int r, int sl, pii val){
push(node, l, r);
if (l > sl || r < sl) return;
if (l == r){
if (l == sl){
tree[node] = val.nd;
mini[node] = val.st;
}
return;
}
int mid = (l + r) / 2;
sett(L(node), l, mid, sl, val);
sett(R(node), mid + 1, r, sl, val);
tree[node] = tree[L(node)] + tree[R(node)];
mini[node] = min(mini[L(node)], mini[R(node)]);
}
void update(int node, int l, int r, int sl, int sr, int val){
push(node, l, r);
if (l > r || l > sr || r < sl) return;
if (l >= sl && r <= sr){
lazy[node] += val;
push(node, l, r);
return;
}
int mid = (l + r) / 2;
update(L(node), l, mid, sl, sr, val);
update(R(node), mid + 1, r, sl, sr, val);
mini[node] = min(mini[L(node)], mini[R(node)]);
}
int pos_query(int node, int l, int r, int val){
push(node, l, r);
if (l == r){
//cout<<"compare : "<<l<<sp<<mini[node]<<sp<<val<<endl;
if (mini[node] >= val) return l;
return INF;
}
int mid = (l + r) / 2;
push(L(node), l, mid);
push(R(node), mid + 1, r);
if (mini[R(node)] < val) return pos_query(R(node), mid + 1, r, val);
return min(pos_query(L(node), l, mid, val), mid + 1);
}
int query(int node, int l, int r, int sl, int sr){
push(node, l, r);
if (l > r ||l > sr || r < sl) return 0;
if (l >= sl && r <= sr) return tree[node];
int mid = (l + r) / 2;
return query(L(node), l, mid, sl, sr) + query(R(node), mid + 1, r, sl, sr);
}
int min_query(int node, int l, int r, int sl, int sr){
push(node, l, r);
if (l > r ||l > sr || r < sl) return INF;
if (l >= sl && r <= sr) {
return mini[node];
}
int mid = (l + r) / 2;
int ans = min(min_query(L(node), l, mid, sl, sr), min_query(R(node), mid + 1, r, sl, sr));
return ans;
}
void build(int node, int l, int r){
mini[node] = INF;
tree[node] = 0;
if (l == r) return;
int mid = (l + r) / 2;
build(L(node), l, mid);
build(R(node), mid + 1, r);
}
int32_t main(){
//fileio();
fastio();
int n;
cin>>n;
build(1, 1, 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), g(n , 0);
iota(v.begin(), v.end(), 1);
iota(g.begin(), g.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];
});
sort(g.begin(), g.end(), [&](int a, int b){
if (x[a] + l[a] == x[b] + l[b]) return x[a] < x[b];
return x[a] + l[a] < x[b] + l[b];
});
for (int i = 0; i < n; i++){
ind[g[i]] = i + 1;
}
int sum = 0;
int ans = 0;
for (auto i : v){
//check
int pos = pos_query(1, 1, n, sum + x[i]);
//cout<<i<<sp<<sum + x[i]<<sp<<pos<<endl;
if (x[i] >= sum - query(1, 1, n, pos, n)){
int first = x[i] + l[i] + query(1, 1, n, ind[i] + 1, n);
int second = x[i];
//cout<<"add: "<<i<<sp<<ind[i]<<sp<<first<<sp<<second<<endl;
sett(1, 1, n, ind[i], {first, second});
update(1, 1, n, 1, ind[i] - 1, second);
ans++;
sum += x[i];
}
}
//cout<<endl;
cout<<ans<<endl;
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
