import java.util.HashMap;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        sc.nextLine();
        String [] grid = new String[n];
        for (int i = 0; i < n; i++) {
            grid[i] = sc.nextLine();
        }
        HashMap<String, Integer> map = new HashMap<>();
        for (int j = 0; j < m; j++) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < n; i++) {
                sb.append(grid[i].charAt(j));
            }
            String key = sb.toString();
            map.put(key, map.getOrDefault(key, 0) + 1);
        }
        int ans = 0;
        Set<String> keySet = map.keySet();
        for (String key : keySet) {
            ans = Math.max(map.get(key), ans);
        }
        System.out.println(ans);
    }
}