import sys

cnts = {}

for line in sys.stdin:

    alpha_line = [x.lower() for x in list([c for c in list(line) if c.isalpha()])]

    for c in alpha_line: 

        cnts[c] = cnts.get(c,0) + 1

 

for c in range(ord('a'),ord('z')+1): print((chr(c),':',cnts.get(chr(c),0)))
import sys

cnts = {}

for line in sys.stdin:

    for c in list(line.lower()): cnts[c] = cnts.get(c,0) + 1

 

for c in range(ord('a'),ord('z')+1): print((chr(c),':',cnts.get(chr(c),0)))
import sys

cnts = {}
for line in sys.stdin:
    alpha_line = [x.lower() for x in list([c for c in list(line) if c.isalpha()])]
    for c in alpha_line:
        cnts[c] = cnts.get(c, 0) + 1
for c in range(ord("a"), ord("z") + 1):
    print((chr(c), ":", cnts.get(chr(c), 0)))

import sys

cnts = {}
for line in sys.stdin:
    for c in list(line.lower()):
        cnts[c] = cnts.get(c, 0) + 1
for c in range(ord("a"), ord("z") + 1):
    print((chr(c), ":", cnts.get(chr(c), 0)))

-    alpha_line = [x.lower() for x in list([c for c in list(line) if c.isalpha()])] -    for c in alpha_line: +    for c in list(line.lower()):