program ktsnt;
var i,n:integer;
begin
write('nhap n='); readln(n);
if n<=1 then writeln(n,' khong phai la so nguyen to') else
begin
i:=2;
while (n mod i <> 0) do i:=i+1;
if i=n then writeln(n,' la so nguyen to') else writeln(n,' khong phai la so nguyen to');
end;
readln
end.
uses crt;
var n,kt,i:integer;
begin
clrscr;
write('n='); readln(n);
kt:=0;
for i:=2 to trunc(sqrt(n)) do
if n mod i=0 then
begin
kt:=1;
break;
end;
if kt=0 then writeln(n,' la so nguyen to')
else writeln(n,' la hop so');
readln;
end.