#include <iostream>
#include <vector>
using namespace std;
 
void dfs (int v, vector <vector <int>>& g, vector<bool>& visited, int& res) {
    visited[v] = true;
    res++;
 
    for (auto i : g[v]) {
        if (!visited[i]) {
            dfs(i, g, visited, res);
        }
    }
 
}
 
int main()
{
    int n, me;
    cin >> n >> me;
 
    vector <vector <int>> g(n + 1, vector <int> ());
 
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            bool t;
            cin >> t;
 
            if (t) {
                g[i].push_back(j);
            }
        }
    }
 
    int res = -1;
    vector <bool> visited(n + 1, false);
 
 
    dfs(me, g, visited, res);
 
    cout << res;
    return 0;
}

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3 1
0 1 0
1 0 1
0 1 0