#include <bits/stdc++.h>
using namespace std;
const int N = 110;
int g[N][N];
bool used[N];
int c = 0;
int n, s;
void dfs(int v) {
    used[v] = true;
    c++;
    for (int i = 0; i < n; i++) {
        if (g[v][i] == 1 && !used[i])
            dfs(i);
    }
}

int main() {
    cin >> n >> s;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cin >> g[i][j];
        }
    }
    dfs(s - 1);
    cout << c;
}