#include<iostream>
#include<algorithm>
using namespace std;
bool Cmp(int a, int b)
{
return a < b;
}
int main()
{
int n, m;
int nsize;
int msize;
cin >> n >> m;
nsize = n; msize = m;
int* nptr = new int[n];
int* mptr = new int[m];
for (int i = 0; i < n; i++)
cin >> nptr[i];
for (int i = 0; i < m; i++)
cin >> mptr[i];
sort(mptr, mptr + m,Cmp);
int cur=0;
while (nsize && msize)//n->apple
{
int pos = -1;
for (int i = m-1; i >=0; i--)
{
if (mptr[i] < nptr[cur] && mptr[i])
{
pos = i;
mptr[i] = 0;
break;
}
}
nsize--;
cur++;
if (pos != -1)
msize--;
}
cout << msize;
system("pause");
return 0;
}