#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ll long long
#define rep(i,a,b) for (int i = a; i <= b; i++)
#define per(i,a,b) for (int i = a; i >= b; i--)
#define fi first
#define se second
#define pii pair<int,int>
#define pb push_back
#define all(v) (v).begin(), (v).end()
const int MAXN = 1e6+10;
const int INF = 1e18 + 5;
const int MOD = 1e9+7;
pii a[MAXN];
void solve() {
int n,k;cin >> n >> k;
rep(i,1,n) cin >> a[i].fi;
rep(i,1,n) cin >> a[i].se;
sort(a+1,a+n+1);
int cur = 0, ans = 0;
rep(i,1,n) {
if(a[i].fi <= cur) cur += a[i].se,ans++;
}
cout << ans << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(nullptr);
int tt = 1;
//cin >> tt;
while (tt--) solve();
return 0;
}
