second simple problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg99667] second simple problem*From*: Francisco Gutierrez <fgutiers2002 at yahoo.com>*Date*: Sun, 10 May 2009 05:19:36 -0400 (EDT)

Dear sirs: I have the following list: ex={1,5,7,4,"M",6,7,8,9,1,"M",3} I want to replace the M's in the following way: the first M by 5, and the second by2. Thus I have a replacement list rL={5,2} The problem is to get ={1,5,7,4,5,6,7,8,9,1,2,3} How can I do this in the most general form (for any length of ex and any number of values of "M")? Thanks Francisco

**Follow-Ups**:**Re: second simple problem***From:*DrMajorBob <btreat1@austin.rr.com>

**Re: second simple problem***From:*Adriano Pascoletti <adriano.pascoletti@dimi.uniud.it>