var n:integer;
function ktnt(k:integer):boolean;
var i,d:integer;
begin
d:=0;
for i:=1 to k do
if k mod i=0 then d:=d+1;
if d=2 then ktnt:=true
else ktnt:=false;
end;
begin
write('n=');readln(n);
ì kt(n) then writeln(n,' la snt ')
else writeln(n,' ko phai snt ');
readln;
end.
program bai2;
uses crt;
var n:integer;
function nt(n:integer):boolean;
var i:integer;
begin
nt:=true;
if n<2 then nt:=false;
for i:=2 to n div 2 do
if n mod i=0 then nt:=false;
end;
begin
clrscr;
write('nhap n=');readln(n);
if nt(n) then writeln(n,' la so nt')
else writeln(n,' khong la so nt');
readln;
end.
uses crt;
var n,i,dem:integer;
begin
clrscr;
write('nhap so nguyen duong n:');readln(n);
dem:=0;
for i:=1 to n do if n mod i=0 then dem:=dem+1;
if (n<2) or (dem <> 2) then writeln(n,' khong phai la so nguyen to') else
if dem=2 then writeln(n,' la so nguyen to');
readln
end.
uses crt;
var n,i,x:integer;
begin
write('nhap n:');readln(n);
x:=0;
for i:=2 to n-1 do
if n mod i=0 then x:=1;
if x=0 then writeln(n, ' la so nguyen to')
else writeln(n, ' ko la so nguyen to');
readln;
end.