【-1+1/100】*【-1+1/101】*【-1+1/102】*...*【-1+1/2011】.
=【1-1/100】*【1-1/101】*【1-1/102】*...*【1-1/2011】.
=99/100*100/101*101/102*.*2010/2011
=99/2011