Write a program which counts and reports the number of each alphabetical letter. Ignore the case of characters.
text = input()
for i in [chr(i) for i in range(97,97+26)]:
    print(i, ":", text.count(i))
try:
    text = ""
    while True:
        text += input()
except:
    for s in [chr(k) for k in range(97,97+26)]:
        print(s,":",text.lower().count(s))