#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
/*
t[j] - t[i] >= abs(a[i] - a[j])
t[j] - t[i] >= a[i] - a[j] and t[j] - t[i] >= a[j] - a[i]
t[j] + a[j] >= t[i] + a[i] and t[j] - a[j] >= t[i] - a[i]
*/
const int M = 5e5 + 25;
int n, m;
array <ll, 2> a[M];
int vis[M];
void solve () {
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> a[i][0];
}
for (int i = 1; i <= m; i++) {
cin >> a[i][1];
}
sort(a + 1, a + m + 1);
for (int i = 1; i <= m; i++) {
a[i] = {a[i][0] - a[i][1], a[i][0] + a[i][1]};
}
int cnt = 0;
for (int i = 1; i <= m; i++) {
cnt += !vis[i];
vis[i] = 1;
int pos = 0;
for (int j = i + 1; j <= n; j++) {
if (!vis[j] && a[j][0] >= a[i][0] && a[j][1] >= a[i][1]) {
if (pos == 0 || a[j][0] < a[pos][0] || (a[j][0] == a[pos][0] && a[j][1] < a[pos][1])) {
pos = j;
}
}
}
vis[pos] = 1;
}
cout << cnt << '\n';
}
signed main () {
ios::sync_with_stdio(0); cin.tie(0);
int tc = 1; //cin >> tc;
while (tc--) solve();
}
