use Algorithm::Diff qw(diff sdiff LCS traverse_sequences);                      
my @seq1= split //,"1  AGCTGATCGAGCTAGTACCCTAGCTC 26";
my @seq2 =split //,"15 AGCTGATCGAGCTAGTACCCTATCTC 40";

my  @diffs = diff( \@seq1, \@seq2 );
foreach (@diffs) {
    foreach (@{$_}) {
       print join " " => @{$_},"\n";        
    }
    print "\n";
    
}