The number of a 5 euro banknote starts with a land code of two letters, followed by 10 digits. for example, the land code ue stands for france. if we replace the letters of the alphabet by their two-digit positions in the alphabet (e. g. ue is replaced by 21 05), we find a number of in total 14 digits. it appears that the obtained number always equals 7 (mod 9). is this code 1-error correcting? if so, why? if not, give an example of a number of a bank note that has one error in it that cannot be corrected.