var i,n,m,c,x,t, l, r:integer;
    a,b:array[1..1000000] of integer;
function bin(i,j:integer;var x:integer):integer;
     var m:integer;
begin
     if l>r then
        bin:=-1 else begin
        m:=(l+r) div 2;
        if a[m]<x then bin:=bin(m+1,r,x) else
        if a[m]>x then bin:=bin(l,m-1,x) else
        bin:=m;
     end;
end;
begin
     read(n);
             for i:=1 to n do read(a[i]);
     read(m);
             for i:=1 to m do read(b[i]);
     for i:=1 to m do
         if (bin(1,n, b[i])<>(-1)) then
            inc(c);

     write(c);
end.