var i: integer;
begin
for i:=1 to 50 do begin
if (i mod 2 = 0) then write(0, ' ')
else write(i, ' ');
end;
end.
var i: integer;
begin
for i:=1 to 50 do begin
if (i mod 2 = 0) then write(0, ' ')
else write(i, ' ');
end;
end.