var
    a:array[1..1000000] of integer;

function bin(l, r: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;

var
    n, m, i: integer;
    c: integer;
    b: array [1..1000000] of integer;

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.