A. Colors
time limit per test
2 seconds
memory limit per test
1024 megabytes
input
standard input
output
standard output

Yuuki is writing a problem and is coming up with the colors to use in the example.

Unfortunately, he wants to refer to each color with a one-character string corresponding to its first letter. This means he cannot use two colors that share the same first letter.

Given a list of $$$n$$$ color suggestions (one word, all uppercase letters), count the maximum number of colors he can use in the problem.

Input

The first line contains a single integer $$$n$$$ ($$$1 \le n \le 1000$$$) — the number of color suggestions.

Each of the next $$$n$$$ lines contains a single string $$$s_i$$$ consisting of uppercase Latin letters ($$$1 \le |s_i| \le 20$$$) — a color suggestion.

Output

Print a single integer — the maximum number of colors Yuuki can use.

Examples
Input
5
RED
BLUE
GREEN
ROSE
BLACK
Output
3
Input
6
LIMEGREEN
LEMONYELLOW
LILAC
LIGHTBLUE
LICORICE
LAVENDAR
Output
1
Note

In the first testcase, Yuuki can choose the colors RED, GREEN, and BLACK which have first letters R G B respectively. It can be shown that Yuuki cannot choose more than three colors.

In the second testcase, Yuuki cannot choose more than one color, as any two colors share the same first letter.