unit Unit2;

interface
Function ASS(N:integer; B:real):real;

implementation
Function ASS(N:integer; B:real):real;
var
    DB:real;A:array[1..15] of real; I:integer;
begin
    A[1]:=Exp(-B) / B;
    If N = 1 Then
      ASS:=A[N]
    else
    begin
        DB:=1 / B;
        For I:=2 To N do
          A[I]:=A[1] + DB * (I - 1) * A[I - 1];
        ASS:=A[N]
    end;
end;
end.