program Task1;

  function Power(x, y: real): real;
  begin
    if x > 0 then
      Power := exp(y * ln(x));
    if x = 0 then
      Power := 0;
    if x < 0 then
      Halt(1);
  end;

  function F(a, m, p: real): real;
  begin
    F := (Power(a, p) + Power(a, -p)) / (2 * Power(a, m) - Power(a, m - p));
  end;

var
  a, m, p: real;
begin
  a := 3;
  m := 5;
  p := 7;
  writeln(F(a, m, p): 0: 6);
end.