function yoba(n: longword):longword;
var
  i: longword;
  a: array of longword;

begin
   SetLength(a,n+1);

   a[1]:=1;
   for i:=2 to n do
     a[i]:= i - a[a[i-1]];
   yoba:=a[n];
end;

begin
  writeln(yoba(50000000));
  readln;
end.