var
   i, j, n, p, q: longint;
   Fi, Fj, Fi1, Fn: extended;
   F: array [1..2, 1..2] of extended;

begin
     readln(i, Fi, j, Fj, n);

     F[1, 1] := 1; F[1, 2] := 0;
     F[2, 1] := 0; F[2, 2] := 1;
     if i < j then begin
        q := 2;
        for p := i + 2 to j do begin
            q := 3 - q;
            F[q, 1] := F[q, 1] + F[3 - q, 1];
            F[q, 2] := F[q, 2] + F[3 - q, 2];
        end;
     end
     else begin
        q := 1;
        for p := i - 1 downto j do begin
            q := 3 - q;
            F[q, 1] := F[q, 1] - F[3 - q, 1];
            F[q, 2] := F[q, 2] - F[3 - q, 2];
        end;
     end;
     Fi1 := (Fj - Fi * F[q, 1]) / F[q, 2];

     F[1, 1] := 1; F[1, 2] := 0;
     F[2, 1] := 0; F[2, 2] := 1;
     if i < n then begin
        q := 2;
        for p := i + 2 to n do begin
            q := 3 - q;
            F[q, 1] := F[q, 1] + F[3 - q, 1];
            F[q, 2] := F[q, 2] + F[3 - q, 2];
        end;
     end
     else begin
        q := 1;
        for p := i - 1 downto n do begin
            q := 3 - q;
            F[q, 1] := F[q, 1] - F[3 - q, 1];
            F[q, 2] := F[q, 2] - F[3 - q, 2];
        end;
     end;
     Fn := Fi * F[q, 1] + Fi1 * F[q, 2];

     if Fn = 0 then writeln(0) else writeln(Fn: 0: 0);
end.