1 var i:longint; 2     n,k,ans:int64; 3 procedure main; 4  begin 5  readln(n); 6  ans:=n; 7  for i:=2 to trunc(sqrt(n)) do 8   if n mod i=0 then 9    begin10    k:=0;11     while n mod i=0 do12      begin13       inc(k);14       n:=n div i;15      end;16     inc(ans,ans*(i-1)*k div i);17    end;18  if n<>1 then inc(ans,ans*(n-1)*1 div n);19  writeln(ans);20  end;21 begin22  main;23 end.