file1 = CTACTCTCTCGTTTCCTAGGCTC
file2 = CTACTCTCTCATTTCCTAGGCTC
                  ^

file1 = CTACTCTCTCGTTTCCTAGGCTC
file2 = CTACTCTCTCATTTCCTAGGCTC
                  ^

file1 = CTACTCTCTCGTTTCCTAGGCTC
file2 = CTACTCTCTCATTTCCTAGGCTC
                  ^