program so_nguyen_to;

uses crt;

var a,i,n: integer; dem:byte;

begin

write('hay nhap n '); readln(n);

dem:=0;

for i:=1 to n do

begin

 for a:=1 to i do

 if (i mod a=0) then dem:=dem+1;

 if (dem=2) then write(i,' ; ');

end;

readln

end.

uses crt;
var i,n:longint;
function nt(a:longint):boolean;
var i:longint;
begin
   i:=2;
   while a mod i<>0 do inc(i);
   nt:=i=a;
end;
begin
clrscr;
   write('n=');readln(n);
   if n<2 then writeln('Khong co so nguyen to nao be hon n!') else
      for i:=2 to n do
         if nt(i) then write(i,';');
readln
end.

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