uses crt;
var n,i: word;
function nt(n: word): boolean;
var i: word;
d: byte;
begin
d:=0;
for i:=1 to n do
if n mod i=0 then inc(d);
if d=2 then nt:=true else nt:=false;
end;
begin
clrscr;
repeat
clrscr;
write ('nhap n: '); readln (n);
if n<0 then writeln ('dieu kien n>=0, vui long nhan enter va nhap lai');
until n>=0;
writeln ('Cac so nguyen to be hon hoac bang ',n,' la: ');
for i:=1 to n do
if nt(i) then write (i:3);
readln;
end.
