a)
uses crt;
var i,n:integer;
begin
clrscr;
repeat
write('Nhap n='); readln(n);
until n<100;
if n mod 2=0 then
begin
for i:=0 to n do
if i mod 2=0 then write(i:4);
end
else writeln(n,' khong la so chan');
readln;
end.
b)
uses crt;
var i,n:integer;
begin
clrscr;
repeat
write('Nhap n='); readln(n);
until n<100;
if n mod 2=1 then
begin
for i:=1 to n do
if i mod 2=1 then write(i:4);
end
else writeln(n,' khong la so le');
readln;
end.