var n:longint;
a:array [1..1000] of longint;
i:integer;
begin
writeln('vvedite dlinnu massiva');
readln(n);
writeln('vvedite massiv');
for i:=1 to n do readln(a[i]);
for i:=1 to n do
if i mod 2=0 then writeln(a[i]);
end.