#include <bits/stdc++.h>
using namespace std;
const int N = 100100;
int n, a[N], p[N], v[N];
bool ok(int x){
for (int i = x - 1; i >= 0; i--)
if (p[i] > v[n - 1 - (x - 1 - i)])
return 0;
return 1;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef _LOCAL
freopen("in.txt","r",stdin);
#endif // _LOCAL
cin >> n;
for (int i = 0; i < n; i++)
cin >> a[i];
for (int i = 0; i < n; i++)
cin >> p[i];
sort(p, p + n);
for (int i = 0; i < n; i++)
cin >> v[i];
sort(v, v + n);
int l = 0, r = n;
while (l < r){
int md = (l + r + 1) >> 1;
if (ok(md))
l = md;
else r = md - 1;
}
cout << l;
return 0;
}