#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define mp make_pair
#define F first
#define S second
#define pb push_back
#define ll long long
const int N = 100010;
const int INF = 0x3f3f3f3f;
const ll mod = 1e9+7;
int p[N];
int v[N];
int f(int x,int y) {
if(x==0||y==0) return 0;
if(v[x]>p[y]) return 1+f(x-1,y-1);
return f(x,y-1);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n,a;
cin>>n;
for(int i=0;i<n;i++) {
cin>>a;
}
for(int i=0;i<n;i++) {
cin>>p[i];
}
for(int i=0;i<n;i++) {
cin>>v[i];
}
sort(p+1,p+n+1);
sort(v+1,v+n+1);
cout<<f(n,n)<<"\n";
return 0;
}
