var n,s,r,i,c:integer;
a,b:array[1..10] of integer;
begin
read(n,s,r);
for i:=1 to s do read(a[i]);
for i:=1 to r do read(b[i]);
 c:=s;
for i:=1 to s do
if (a[i]=b[i]) or (a[i]=b[i]-1) or   (a[i]=b[i]+1) then  begin c:=c-1; b[i]:=0; end;
writeln(c) ;
end.