uses crt;
function soPhongPhu(n: longint): boolean;
var s,i: longint;
begin
    s := 0;
    for i := 1 to n - 1 do
        if n mod i = 0 then s := s + i;
    if s > n then exit(true) else exit(false);
end;
var n,i: longint;
begin
    readln(n);
    i := n;
    while not(soPhongPhu(i)) do inc(i);
    write(i);
end.

program DivisorSum;

function DivisorSum(x: Integer): Integer;
var
  d, sum: Integer;
begin
  if x = 1 then
    Result := 0
  else
  begin
    sum := 1;
    for d := 2 to Trunc(Sqrt(x)) do
    begin
      if x mod d = 0 then
      begin
        sum := sum + d;
        if x div d <> d then
          sum := sum + x div d;
      end;
    end;
    Result := sum;
  end;
end;

var
  l, r, count, i: Integer;
begin
  Readln(l, r);
  count := 0;
  for i := l to r do
    if DivisorSum(i) > i then
      Inc(count);
  Writeln(count);
end.