// noi 2023 final round
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vi vector<long long>
#define all(x) x.begin(), x.end()
#define endl "\n"
#define pr pair<ll, ll>
#define ff first
#define ss second
void solution();
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
solution();
return 0;
}
void solution() {
ll n, k; cin >> n >> k;
vector<pr> a(n);
for (int i = 0; i < n; i++) cin >> a[i].ff;
for (int i = 0; i < n; i++) cin >> a[i].ss;
ll x = 0;
sort(all(a));
int i = 0;
for (; i < n; i++) {
if (x < a[i].ff) break;
x += a[i].ss;
}
cout << i << endl;
}
