#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main() {
    int n;
    cin >> n;
    vector<int> myH(n);
    for (int i = 0; i < n; i++) {
        cin >> myH[i];
    }
    sort(myH.begin(), myH.end());
    vector<int> tianH(n);
    for (int i = 0; i < n; i++) {
        cin >> tianH[i];
    }
    vector<bool> used(n, false);
    int win = 0;
    for (int i = 0; i < n; i++) {
        int tianjiH = tianH[i];
        bool found = false;
        for (int j = 0; j < n; j++) {
            if (!used[j] && myH[j] > tianjiH) {
                win++;
                used[j] = true;
                found = true;
                break;
            }
        }
        if (!found) {
            for (int j = 0; j < n; j++) {
                if (!used[j]) {
                    used[j] = true;
                    break;
                }
            }
        }
    }
    cout << win << endl;
    return 0;
}