#include <bits/stdc++.h>
using namespace std;

vector<pair<int, int>> graph[2001];
int distances[2001];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    freopen("pathmgep.in", "r", stdin);
    freopen("pathmgep.out", "w", stdout);
    int n, start, finish;
    cin >> n >> start >> finish;
    start--;
    finish--;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            int weight;
            cin >> weight;
            if (weight != 0 && weight != -1) {
                graph[i].push_back({j, weight});
            }
        }
    }

    for (int i = 0; i < n; i++) {
        distances[i] = 1e9 + 1;
    }

    distances[start] = 0;

    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;

    q.push({start, 0});

    while (!q.empty()) {
        pair<int, int> top = q.top();
        q.pop();

        int v = top.first, dst = top.second;

        if (distances[v] < dst) {
            continue;
        }

        for (pair<int, int> e: graph[v]) {
            int u = e.first, len_vtou = e.second;

            int new_dst = dst + len_vtou;
            if (new_dst < distances[u]) {
                distances[u] = new_dst;
                q.push({u, new_dst});
            }
        }
    }
    if (distances[finish] != 1e9 + 1) {
        cout << distances[finish] << endl;
    } else cout << -1 << endl;
    return 0;
}

/*
  3 1 2
  0 -1 2
  3 0 -1
  -1 4 0

 3 1 2
 0 -1 2
 3 0 -1
 -1 -1 0

 */