program sieu_nguyen_to;
var n:integer;
{---Ham-nguyen-to---}
function ktnt(k:integer):boolean;
var e:integer;
begin
ktnt:=false;
if k<2 then exit;
for e:=2 to trunc(sqrt(k)) do
if k mod e=0 then exit;
ktnt:=true;
end;
{---Ham-sieu-nguyen-to---}
function ktsnt(x:integer):boolean;
begin
ktsnt:=false;
while x>0 do
begin
if ktnt(x)=false then exit;
x:=x div 10;
end;
ktsnt:=true;
end;
{---Chuong-trinh-chinh---}
BEGIN
clrscr;
write('Nhap so can kiem tra: '); readln(n);
if ktsnt(n) then write('Yes') else write('No');
readln;
end.
