int main (){

int n,m,i,sum,j,ls,max;

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

int pg[n],tt[m];

for (i=0;i<n;i++)

{scanf ("%d",&pg[i]);

}

for (i=0;i<m;i++)

{scanf ("%d",&tt[i]);

}

sum=m;

for (i=0;i<n;i++)

{max=0;

ls=-1;

for (j=0;j<m;j++)

{if ((pg[i]>tt[j])&&(tt[j]>max))

{max=tt[j];

ls=j;

}

}

if (max==0){continue;}

tt[ls]=10000;

sum--;

}

printf ("%d",sum);

return 0;

}