var n,i,j,k,min:int64;
    nr1,nr2,nrb:longint;
    f,g:text;
    kv:array[1..22] of longint;
procedure citire;
var i:byte;
begin
assign(f,'light2.in'); reset(f);
readln(f,n);
readln(f,k);
for i:=1 to k do begin
read(f,kv[i]);
if min=0 then min:=kv[i] else
        if min>kv[i] then min:=kv[i];
                 end;
end;

begin
citire;
for i:=min to n do begin
nr1:=0;
  for j:=1 to k do
     if i mod kv[j]=0 then nr1:=nr1+1;
if nr1 mod 2=1 then nrb:=nrb+1;
end;
assign(g,'light2.out'); rewrite(g);
writeln(g,nrb);
close(f); close(g);
end.