The most binary substring 如何来编写呢

Question

Problem Description
Everybody knows the number is saved with the binary string in the computer. Now, their have N (1 <= N <= 1000) binary strings I tell you, your task is tell me what is the most binary substring with K (1 <= K <= L) characters in the strings I give you. The length of each string is L (1 <= L <= 60). Output times of the most appearing binary substring.

Input
Each line will contain three numbers N, L, K.
Following N lines, represent N binary strings.

Output
One answer one line.

Sample Input
2 6 3
101011
110101
2 6 4
101011
110101

Sample Output
4
2