文件目录

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n, u[50005] = {}, v[50005] = {};
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> u[i];
    for (int i = 1; i <= n; i++)
        cin >> v[i];
    sort(u + 1, u + 1 + n);
    sort(v + 1, v + 1 + n);
    int ans = 0;
    for (int i = 1, j = 1; i <= n; i++)
    {
        if (u[i] >= v[j])
        {
            j++;
            ans++;
        }
    }
    cout << ans;
    return 0;
}