import java.util.*;

public class Test_1874 {
    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner s = new Scanner(System.in);
        int h, w, n;
        h = s.nextInt();
        w = s.nextInt();
        n = s.nextInt();

        String[] a = new String[n];
        for (int i = 0; i < n; i++) {
            a[i] = s.nextLine();
            if (a[i].isEmpty()) {
                a[i] = s.nextLine();
            }
        }

        if (n == 1) {
            System.out.println("1");
            return;
        }

        int b, c = 0, d = 0, list = 0, page = 0;

        for (int i = 0; i < n; i++) {
            b = (a[i].length() + 1);

            if (i == 0) {
                c = a[i + 1].length();

                if (b + c == w) {
                    list++;

                } else if (b + c < w) {
                    d = b + c;
                    c = a[i + 2].length();
                    if ((d + c) == w) {
                        list++;
                    } else if ((d + c) < w) {

                    } else {
                        list++;
                    }
                } else {
                    list++;
                }
            } else {

                if ((b + d) == w) {
                    list++;

                } else if ((b + d) < w) {
                    d = d + b;
                    c = a[i + 1].length();
                    if ((d + c) == w) {
                        list++;
                    } else if ((d + c) < w) {

                    } else {
                        list++;
                    }
                } else {
                    list++;
                }

            }

            if (list == h) {
                page++;
                list = 0;
            } else if (i == (n - 1)) {
                if(list>=1){
                    page++;
                }

            }

        }
        System.out.println(page);

    }
}