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Imagine a school that children attend for years. In each year, there are a certain number of groups started, marked with the letters. So if years = 7 and groups = 4For the first year, the groups are 1a, 1b, 1c, 1d, and for the last year, the groups are 7a, 7b, 7c, 7d.

Write a function that returns the groups in the school by year (as a string), separated with a comma and space in the form of "1a, 1b, 1c, 1d, 2a, 2b (....) 6d, 7a, 7b, 7c, 7d".

Examples:

csSchoolYearsAndGroups(years = 7, groups = 4) ➞ "1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d, 4a, 4b, 4c, 4d, 5a, 5b, 5c, 5d, 6a, 6b, 6c, 6d, 7a, 7b, 7c, 7d"

""


#your code here
def csSchoolYearsAndGroups(years, groups):

