use strict;
use warnings;

my $line = "GGCTTTCCGTTGTTGCTGGGTGTGGGGGGCGGGCGAGATTGGAAGAGCACACGTCTGAACTCCAGTCACGCCAATATCTCGTATGCCGTCTTCTGCTTGAAAAAAGGGGTGGGGGGGAGGGGGGGCGGGGGGGGGGGGGGGAGGGGGGGAG";
my @pieces = split /(G{10,})/, $line;
print "$_\n" for @pieces;