//implementation of the simplest test for being prime
//author: Michal Pilipczuk
//XIV Secondary High School, Warsaw, Poland

program napale;
uses bignumber;
var hand_in:text;
i,j:longint;
wej:string;
flag:boolean;
begin
    assign(hand_in,'/home/k03_a/michaj/.homepage/napale.in');
    reset(hand_in);
    readln(hand_in,wej);
    close(hand_in);
    if not(sprawdz(wej)) then
    writeln('WRONG INPUT')
    else
    begin
	i:=longintuj(wej,10);
	flag:=true;
	for j:=2 to trunc(sqrt(i)) do
	begin
    	    if (i mod j)=0 then
	    begin
		flag:=false;
		break;
	    end;
	end;
	writeln(flag);
    end;
end.