Maximum Strings Buildable from at Most K Letters

Choose at most K letters from a–j (chosen letters can be reused); find the maximum number of the given strings that can be built completely.

This site's standard input/output format and any supplementary ranges follow this problem's description.

输入格式

The first line contains n K (1≤n≤100000, 0≤K≤10); each of the next n lines is a non-empty lowercase string containing only a–j. The total length is ≤200000 (site supplement).

输出格式

Output the maximum number of strings that can be built.

样例 1

输入：

5 3
adf
jjbh
jcg
eijj
adf

输出：

2

样例 2

输入：

2 3
abcd
efgh

输出：

0

样例 3

输入：

5 4
bc
edf
fde
dge
abcd

输出：

3