The algorithm of to find the combination is:

   
       where, k = (m>(n-m))?m:(n-m)

 Another think have to noted that the resuelt of (k+1)*(k+2)��.n can be as large as it cross the limit. It is also true for  1*2*3*�*k. So first determine the result (k+1)/1, then multiply the result of it with (k+2)/2 and so on.

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