#include<cstdio>

using namespace std;

int n,m,i,ans,sum=0,a[302]={},b[302]={};

int main()

{

scanf("%d%d",&n,&m);

for (int q=0;q<n;q++) {scanf("%d",&i);a[i]++;}

for (int q=0;q<m;q++) {scanf("%d",&i);b[i]++;}

for (int q=300;q>=1;q--)

{

if (sum>b[q]) { ans+=b[q];sum-=b[q];}

else {ans+=sum;sum=0;}

sum+=a[q];

}

ans=m-ans;

printf("%d",ans);

//system("pause");

return 0;

}