use strict;
use warnings;

my $str = join '', <DATA>;

my $i = 0;
1 while $str =~ s{
    ^((?>\w+))(?!\d)(.*?)
    ^\1(?!\d)
}{"$1$2$1" . ++$i}msxeg;
print $str;

__DATA__
George Fortran
Jessi Heavens
Bill Clinton
Barack Obama
Bill Gates
Steve Jobs
Bill Green
George Bush