$.$ For example no global variables are allowed to be used, break and continue should never be used in loops, code that does not follow the given directions $($like forbidden use of libraries, methods and operations$).$

Returns a dictionary with the frequency count of each alphabet letter $($in lowercase$)$ in txt$.$ You

cannot make assumptions about the contents in txt$.$

Preconditions and Postconditions

txt: non$-$empty str

Returns: dict $->$ frequency count