I coded this from a puzzle a friend showed to me. 
#!/usr/bin/perl -w
use strict;undef $/;$_=<>;while(m+^(\d)(\1*)+)
{print length($1.$2),$1;s;$1$2;;;}
########################################################
#
#  This works best with the numbers 1, 2, and 3.
#
########################################################

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In reply to 123 Digit Counter by rje

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