#include <cstdio>
#include <algorithm>
#include <vector>

#define N 101

using namespace std;

vector<int> graph[N];
int n, s, res;
bool was[N];

void dfs(int v) {
    was[v] = true;
    res++;
    for (int i = 0; i < graph[v].size(); i++) {
        int u = graph[v][i];
        if (!was[u]) dfs(u);
    }
}

int main() {
    scanf("%d %d ", &n, &s);
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++) {
            int a;
            scanf("%d", &a);
            if (a)
                graph[i].push_back(j);
        }

    dfs(s);
    printf("%d", res);
    return 0;
}