import java.util.*;

class Solution {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int R = in.nextInt();
        int C = in.nextInt();
        int K = in.nextInt();
        int count1 = 0;
        in.nextLine();
        for (int i = 0; i < R; i++) {
            String val = in.nextLine();
            for (int j = 0; j < val.length(); j++)
                count1 += val.charAt(j) == '1' ? 1 : 0;
        }
        System.out.println(R * C < K ? (R * C - 1) : (count1 + K));
    }
}