/GIDA - Giao đấu (OLP 2014)

              var a,b:array[0..100000] of int64;
        n,i,j,kq:longint;
    procedure sort(l,r: longint);
          var
             i,j,x,y: longint;
          begin
             i:=l;
             j:=r;
             x:=a[(l+r) div 2];
             repeat
               while a[i]<x do
                inc(i);
               while x<a[j] do
                dec(j);
               if not(i>j) then
                 begin
                    y:=a[i];
                    a[i]:=a[j];
                    a[j]:=y;
                    inc(i);
                    j:=j-1;
                 end;
             until i>j;
             if l<j then
               sort(l,j);
             if i<r then
               sort(i,r);
          end;
    
    procedure sort1(l,r: longint);
          var
             i,j,x,y: longint;
          begin
             i:=l;
             j:=r;
             x:=b[(l+r) div 2];
             repeat
               while b[i]<x do
                inc(i);
               while x<b[j] do
                dec(j);
               if not(i>j) then
                 begin
                    y:=b[i];
                    b[i]:=b[j];
                    b[j]:=y;
                    inc(i);
                    j:=j-1;
                 end;
             until i>j;
             if l<j then
               sort1(l,j);
             if i<r then
               sort1(i,r);
          end;
    begin
    readln(n);
    for i:=1 to n do
    read(a[i]);
    readln;
    for i:=1 to n do
    read(b[i]);
    sort(1,n);sort1(1,n);
    i:=1;
    j:=1;
    while (i<=n) and (j<=n) do
    begin
    if b[i]>a[j] then
    begin
    inc(kq);
    inc(i);
    inc(j);
    end
    else
    inc(i);
    end;
    write(kq);
    end.