#include <iostream>
#include <vector>
#include <queue>
#include <string>
#include <sstream>
#include <cmath>
#include <map>
#include <set>
#include <ctime>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>

using namespace std;

#define PR printf
#define SC scanf
#define PB push_back
#define SE second
#define FI first

#define FOR(i, k, n) for(int i = (k); i <= (n); i++)
#define DFOR(i, k, n) for(int i = (k); i >= (n); i--)
#define SZ(a) (int)((a).size())
#define FA(i, v) FOR(i, 0, SZ(v) - 1)
#define RFA(i, v) DFOR(i, SZ(v) - 1, 0)

#define ll long long

void end() {
    cout << endl;
    system("pause");
}



int n, s;
vector<int> a[110];
char t[110] = {};

void DFS(int x) {
    t[x]++;
    FA(i, a[x])
        if (!t[a[x][i]])
            DFS(a[x][i]);
}

int main()
{
    cin >> n >> s;
    FOR(i, 0, n - 1) {
        FOR(j, 0, n - 1) {
            int p;
            cin >> p;
            if (p)
                a[i].push_back(j);
        }
    }

    DFS(s - 1);
    int cnt = 0;
    FOR(i, 0, 109)
        if (t[i])
            cnt++;

    cout << cnt;

    end();
}