#include <bits/stdc++.h>
using namespace std;
#define mnto(x, y) x = min(x, (__typeof__(x)) y)
#define mxto(x, y) x = max(x, (__typeof__(x)) y)
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb emplace_back
typedef vector<int> vi;
typedef vector<ii> vii;
#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 500005
int n, m;
ii ta[MAXN];
vi adj[MAXN];
int p[MAXN * 2];
int mcbm;
bool visited[MAXN];
bool dfs(int u) {
for (int v : adj[u]) {
if (visited[v]) continue;
visited[v] = 1;
if (p[v] == -1 || dfs(p[v])) {
p[v] = u;
return 1;
}
}
return 0;
}
bool isPos(int i, int j) {
return ta[j].FI - ta[i].FI >= abs(ta[j].SE - ta[i].SE);
}
int main() {
scanf("%d%d", &n, &m);
REP (i, 0, m) {
scanf("%d", &ta[i].FI);
}
REP (i, 0, m) {
scanf("%d", &ta[i].SE);
}
sort(ta, ta + m);
REP (i, 0, m) {
REP (j, i + 1, m) {
if (isPos(i, j)) {
//printf("%d %d\n", i, j);
adj[i].pb(j + m);
}
}
}
memset(p, -1, sizeof p);
REP (i, 0, m) {
REP (j, 0, m * 2) {
visited[j] = 0;
}
if (dfs(i)) {
mcbm++;
}
}
printf("%d\n", m - mcbm);
return 0;
}
