  The famous Whitney formula relates the winding number of the smooth generic
curve in the real plane to the number of its self-intersection points counted
with appropriate signs. We extend this formula to smooth immersions of R^n to
R^{2n}. Then use this result together with the general technique of Laplace
integrals to get an explicit formula for the generator of the group H^n of
Stiefel variety V(n,2n).
