program az1;
var
a,b:array[1..2000]of longint;
n,m,k,t,i,j,s:longint;
begin
readln(n,m);
for i:=1 to n do
readln(a[i]);
for i:=1 to m do
readln(b[i]);
for i:=1 to m-1 do
for j:=i+1 to m do
if b[i]>b[j] then
begin
t:=b[i];
b[i]:=b[j];
b[j]:=t;
end;
s:=0;
for i:=1 to n do
for j:=1 to m do
if (a[i]>=b[j])and(b[j]<>0)then
begin
b[j]:=0;
s:=s+1;
break;
end;
writeln(n-s);
end.