Bài 1:
uses crt;
var n,i:integer;
begin
clrscr;
readln(n);
for i:=1 to n do
if i mod 2=0 then write(i:4);
readln;
end.
Bài 2:
uses crt;
var n,i:integer;
begin
clrscr;
readln(n);
for i:=1 to n do
if i mod 2=1 then write(i:4);
readln;
end.