import java.io.*;
public class Test_Ngto{
public
static void main(String args[]){
InputStream
is = System.in;
InputStreamReader
isr = new InputStreamReader(is);
BufferedReader
br = new BufferedReader(isr);
try{
String
n = br.readLine();
long
l = Long.valueOf(n).longValue();
long
range = (long)Math.sqrt(l);
int
ok = 1;
for(int
i=2;i<=range;i++){
if(l
% i == 0) ok = 0; break;
}
if(ok
== 1){
System.out.println("So
nay la nguyen to");
}
else{
System.out.println("So
nay khong la nguyen to");
}
}
catch(IOException
ie){
System.out.print("Error:
" +ie);
}
}
}