program Project3;

{$APPTYPE CONSOLE}

uses
  SysUtils;

const
  MAXIN = 100000;

var
  k, i, j, n, top, k1: integer;
  a, b: array [0..MAXIN] of integer;

function prost(n: integer): boolean;
var
  i: integer;
begin
  prost := true;
  for i := 2 to trunc(sqrt(n)) do
    if (n mod i = 0) then
      prost := false;
end;

begin
  readln(k);
  top := 0;
  k1 := 0;
  n := 50000;
  for i := 2 to n do
    if (prost(i)) then
    begin
      inc(top);
      a[top] := i;
    end;

  for i := 2 to top do
  begin
    if (prost(i)) then
    begin
      inc(k1);
      b[k1] := a[i];
    end;
  end;

  writeln(b[k]);
  readln;
  readln;
end.