Const
N=20;
uses Crt;
var i,k,l:integer;
A:array [1..N] of integer;
B:array [1..N] of integer;
begin
clrscr;
for i:=1 to N do readln(A[i]);
k:=0;
l:=0;
for i:=1 to N do
begin
if (A[i]<0) and (i mod 2=0) then begin
B[k]:=i;
inc(k);
inc(l);
end;
end;
for k:=1 to l do write(B[k]:5);
end.