(* Josephus problem *)
block
var
  k, m, n: integer;

  unit Josephus: function (n, k, m: integer): integer;
  var
    a, j: integer;
  begin
    j := m;
    for a := m + 1 to n do
      j := (j + k) mod a
    od;
    result := j;
  end Josephus;

begin
  n := 41;
  k := 3;
  m := 0;
  writeln("N = ", n: 1, ". K = ", k: 1, ". Final survivor = ", Josephus(n, k, m): 1, ".");
end;