t164

import java.util.Scanner;

public class t164 {
    static int[][] G ;
    static int n;
    static boolean [] used ;
    static void dfs (int v) {
        used[v]=true;
        for (int i=0; i<G.length; i++) {
            if(G[v][i]==1 && !used[i]) {
                dfs(i);
            }}}
    public static void main(String[] args) {

        Scanner in = new Scanner  (System.in);
        n = in.nextInt();
        used= new boolean[n];
        G=new int[n][n];
        int s = in.nextInt()-1;
        for (int i=0; i<n; i++) {
            for (int j=0; j<n; j++) {
                G[i][j]=in.nextInt();
            }}
        dfs(s);
        int count = 0;
        for (int i=0; i<used.length; i++) {
            if (used[i]) {
                count++;
            }
        }
        System.out.println(count);
    }

}