Program wanted;
Uses crt;
Var t: boolean;
n,i: longint;
Begin
clrscr;
t := true;
write('nhap n=');
readln(n);
If n<10 :="false;</p" t="" then=""> While n>=10 Do
Begin
If n<=1 Then t := false;
For i:=2 To trunc(sqrt(n)) Do
If n Mod i=0 Then t := false;
n := n Div 10;
End;
If n<10 p="" then=""> Begin
If n<=1 Then t := false;
For i:=2 To trunc(sqrt(n)) Do
If n Mod i=0 Then t := false;
End;
If t=true Then writeln('n la so sieu nguyen to')
Else writeln('n ko la so sieu nguyen to');
readln
End.