#include <bits/stdc++.h> using namespace std; int n,m; int a[10005],b[10005]; int main() { cin >> n >> m; for (int i = 1;i <= n;i++) cin >> a[i]; for (int i = 1;i <= m;i++) cin >> b[i]; sort (a+1,a+n+1); sort (b+1,b+m+1); int sum = 0; int l = 1; for (int i = 1;i <= n;i++) { if (a[i] >= b[l]) { sum++; l++; } } cout << sum; }