#include <bits/stdc++.h>
#define sz(x) ((int)(x).size())
#define all(x) begin(x), end(x)
#ifdef memset0
#define log(...) fprintf(stderr, __VA_ARGS__)
#else
#define endl '\n'
#define log(...) (void(0))
#endif
using namespace std;
using ll = long long;
using lf = long double;
using ull = unsigned long long;
using lll = __int128;

const int N = 109, M = N * N * 2 * 6;
int n, cnt, ex, ey, p[N][N << 1], dis[M];
vector<int> g[M];

int main() {
#ifdef memset0
  freopen("B.in", "r", stdin);
#endif
  cin.tie(0)->sync_with_stdio(0);

  cin >> n;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j < (i << 1); j++) {
      cin >> p[i][j];
      --p[i][j];
    }
  }
  cin >> ex >> ey;

  map<tuple<int, int, int>, int> mp;
  vector<int> e;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j < (i << 1); j++) {
      int a = p[i][j];
      for (int b = 0; b < 4; b++)
        if (a != b)
          for (int c = 0; c < 4; c++)
            if (a != c && b != c)
              for (int d = 0; d < 4; d++)
                if (a != d && b != d && c != d) {
                  mp[make_tuple(i, j, b << 4 | c << 2 | d)] = ++cnt;
                  if (i == ex && j == ey) {
                    e.emplace_back(cnt);
                  }
                }
    }
  log("! n = %d\n", n);

  for (int i = 1; i <= n; i++)
    for (int j = 1; j < (i << 1); j += 2) {
      int a = p[i][j];
      for (int b = 0; b < 4; b++)
        if (a != b)
          for (int c = 0; c < 4; c++)
            if (a != c && b != c)
              for (int d = 0; d < 4; d++)
                if (a != d && b != d && c != d) {
                  int u = mp[make_tuple(i, j, b << 4 | c << 2 | d)];
                  auto push = [&](int vi, int vj, int va, int vb, int vc, int vd) {
                    if (vi < 1 || vi > n) return;
                    if (vj < 1 || vj >= (vi << 1)) return;
                    if (va != p[vi][vj]) return;
                    int v = mp[make_tuple(vi, vj, vb << 4 | vc << 2 | vd)];
                    g[u].emplace_back(v);
                    g[v].emplace_back(u);
                  };
                  push(i + 1, j + 1, d, b, c, a);
                  push(i, j - 1, b, d, a, c);
                  push(i, j + 1, c, a, d, b);
                }
    }

  fill(all(dis), -1);
  int s = mp[make_tuple(1, 1, 0 << 4 | 2 << 2 | 1)];
  dis[s] = 0;
  queue<int> q;
  q.push(s);
  while (q.size()) {
    int u = q.front();
    q.pop();
    for (int v : g[u])
      if (dis[v] == -1) {
        dis[v] = dis[u] + 1;
        q.push(v);
      }
  }

  int ans = -1;
  for (int u : e)
    if (dis[u] != -1) {
      if (dis[u] < ans || ans == -1) {
        ans = dis[u];
      }
    }
  cout << ans << endl;
}