var f,g:text;
    s,v,t:array[1..50000] of longint;
    n,i,j,d,max,p,mm:longint;

begin
assign(f,'subsir2.in');
reset(f);
readln(f,n);
for i:=1 to n do read(f,v[i]);
close(f);
s[n]:=1;
t[n]:=0;
max:=0;
for i:=n-1 downto 1 do
   begin
     d:=2000000;mm:=0;   t[i]:=0; s[i]:=1;
     for j:=i+1 to n do
        if (s[j]<mm)and(v[j]>v[i])and(v[j]-v[i]<=d) then
           begin
             d:=v[j]-v[i];
             t[i]:=j;
             s[i]:=s[j]+1;
           end;
       if s[i]>max  then
         begin
           max:=s[i]; p:=i;
         end;
   end;
assign(g,'subsir2.out');
rewrite(g);
writeln(g,max);
for i:=1 to max do
   begin
     write(g,p,' ');
     p:=t[p];
   end;
 writeln(g);
close(g);
end.