Spongebob is having a cryptography lesson today!
Today's lesson is about substitution cipher (http://en.wikipedia.org/wiki/Substitution_cipher),
which is a method of encryption whereby every alphabet is replaced by another alphabet.
Cracking a code encrypted by substitution is rather easy due to the flaws of the English Language.
This is because certain letters are more frequently used than others. For example: E is used 11% of the time while Q is only used 0.2%.
As such, Spongebob's teacher, wants spongebob to investigate the frequency of letters of the language used in Bikini-Bottom.
However, there might be thousands of letters, making it very boring for Spongebob to count one by one.
Your Task:
Create a program that count the number of time every letter appears.
Input
The first line of input will be a single integer,
n
n is the total number of letters that follow and 0 <
n < 25001.
The second line of input will be
n letters.
The lettes will all be in lowercase and there are no spaces in between them.
Output
Output the corresponding frequency of each letter, A-Z.
Refer to sample output for more details.
Sample Input
36
thequickbrownfoxjumpedoverthelazydog
Sample Output
a 1
b 1
c 1
d 2
e 4
f 1
g 1
h 2
i 1
j 1
k 1
l 1
m 1
n 1
o 4
p 1
q 1
r 2
s 0
t 2
u 2
v 1
w 1
x 1
y 1
z 1