#include <iostream>
#include <vector>
using namespace std;
int n, s, k = 0;
vector<vector<int> >g(n+1, vector<int>(n+1));
vector<int> visited(n+1, 0);

void dfs(int u)
{
    if(visited[u] == 1)
    {
        return;
    }
    visited[u] = 1;
    k++;
        for(int v = 1; v <= n; v++)
        {
            if(g[u][v])
            {
                dfs(v);
            }
        }

}

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