/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;
int n, m, a[N], b[N];
void solve(){
cin >> n >> m;
for(int i = 1; i <= m; ++i){
cin >> a[i];
}
for(int i = 1; i <= m; ++i){
cin >> b[i];
}
vector<array<int, 3>> A;
for(int i = 1; i <= m; ++i){
A.pb({a[i] + b[i], a[i] - b[i], i});
}
sort(all(A));
int ans = 0;
set<pii> S;
for(auto [x, y, idx]: A){
auto v = S.upper_bound(pii{y + 1, -1 });
if(v == S.begin()) ++ans;
else{
--v;
S.erase(v);
}
S.insert({y, idx});
}
cout << ans;
}
int main(){
cin.tie(0); ios::sync_with_stdio(0);
int tt = 1, aa;
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
while(tt--){
solve();
en;
}
cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
return 0;
}
