program vultur;
var f,g:text;
    v,t:array [1..1002] of word;
    m:array [1..50001] of byte;
    n,i,j,x,y,aux,k,nr:word;
begin
assign(f,'economie.in');
reset(f);
assign(g,'economie.out');
rewrite(g);
readln(f,n);
for i:=1 to n do
    readln(f,v[i]);
for i:=1 to n-1 do
    for j:=i+1 to n do
        if v[i]>v[j] then begin
           aux:=v[i];
           v[i]:=v[j];
           v[j]:=aux;
                          end;
m[v[1]]:=1;
nr:=1;
t[1]:=v[1];
for i:=1 to v[n] div v[1] do
    m[v[1]*i]:=1;
k:=2;
for i:=2 to n do
    if m[v[i]]<>0 then
               else begin inc(nr);
                          for j:=v[n] downto v[1] do if m[j]=1 then m[j+v[i]]:=1;
                          t[k]:=v[i];
                          inc(k);
                   end;
writeln(g,nr);
for i:=1 to k-1 do
    writeln(g,t[i]);
close(f);
close(g);
end.