//
// Created by Emin Alizade on 03.01.22.
// https://g...content-available-to-author-only...b.com/emin-alizada/ADA-Design-and-Analysis-of-Algorithm-e-olymp/blob/master/4000%20-%20Depth%20Search/main.cpp
//
 
#include <iostream>
#define MAX 101
 
using namespace std;
 
int n, g[MAX][MAX], used[MAX], s, counter = 0;
 
void dfsMatrix(int v) {
    used[v] = 1;
    counter++;
 
    for (int i = 1; i <= n; ++i) {
        if (used[i] == 0 && g[v][i] == 1) {
            dfsMatrix(i);
        }
    }
}
 
int main() {
    cin>>n >> s;
 
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            cin >> g[i][j];
        }
    }
 
    dfsMatrix(s);
 
    cout << counter;
 
    return 0;
}

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5 1
0 1 1 0 0
1 0 1 0 0
1 1 0 0 0
0 0 0 0 1
0 0 0 1 0