#include <bits/stdc++.h>

using namespace std;

#define int long long

vector<vector<pair<int, int>>> g;

const int inf = 1e12;

main()
{
  #ifdef _DEBUG
   freopen("in.txt","rt",stdin);
  #endif // _DEBUG

  int n, s, f;
  cin >> n >> s >> f;
  s--, f--;

  g.resize(n);
  for (int i = 0; i < n; i++)
  {
    for (int j = 0; j < n; j++)
    {
      int t;
      scanf("%lld", &t);

      if (t != -1 && (i != j))
        g[i].push_back({j, t});
    }
  }

  vector<bool> used(n, false);
  vector<int> d(n, inf);
  d[s] = 0;

  for (int i = 0; i < n; i++)
  {
    int v = -1;
    for (int j = 0; j < n; j++)
      if (!used[j] && (v == -1 || d[j] < d[v]))
        v = j;

     if (d[v] == inf)
       break;
     used[v] = true;


     for (int j = 0; j < g[v].size(); j++)
     {
       int to = g[v][j].first;
       int len = g[v][j].second;

       if (d[v] + len < d[to])
         d[to] = d[v] + len;
     }
  }

  if (d[f] == inf)
    cout << -1;
  else
    cout << d[f];

}