Determine if a sentence is a pangram. A pangram (Greek: παν γράμμα, pan gramma, "every letter") is a sentence using every letter of the alphabet at least once. The best known English pangram is:
The quick brown fox jumps over the lazy dog.
The alphabet used consists of ASCII letters
z, inclusive, and is case
insensitive. Input will not contain non-ASCII symbols.
It pays off to carefully read the exercise description as this can simplify your solution and make it quite compact.