import std.algorithm, std.conv, std.range, std.stdio, std.string;
import std.container; // SList, DList, BinaryHeap

void main()
{
  auto rd = readln.split;
  auto n = rd[0].to!size_t, v = rd[1].to!size_t;
  auto sx = rd[2].to!int - 1, sy = rd[3].to!int - 1;
  auto gx = rd[4].to!int - 1, gy = rd[5].to!int - 1;
  auto lij = Matrix!int(n.iota.map!(_ => readln.split.to!(int[])).array);

  auto eij = new Edge!int[][](n ^^ 2);
  foreach (p; lij.points!int)
    foreach (sib; sibPoints) {
      auto np = p + sib;
      if (lij.validIndex(np))
        eij[p.x + p.y * n] ~= Edge!int(np.x + np.y * n, lij[np]);
    }

  auto s = sx + sy * n;
  auto g = gx + gy * n;

  int calc()
  {
    auto qi = [s];
    auto dp = new int[](n ^^ 2);
    dp[] = -1;
    dp[s] = 0;

    for (auto r = 1; !qi.empty; ++r) {
      size_t[] ri;
      foreach (q; qi) {
        foreach (e; eij[q]) {
          auto nv = dp[q] + e.w;
          if (nv < v && (dp[e.v] < 0 || dp[e.v] > nv)) {
            if (e.v == g) return r;
            dp[e.v] = nv;
            ri ~= e.v;
          }
        }
      }
      qi = ri;
    }

    return -1;
  }

  writeln(calc);
}

struct Edge(T) {
  size_t v;
  T w;
}

struct Point(T) {
  T x, y;

  point opBinary(string op)(point rhs) {
    static if (op == "+") return point(x + rhs.x, y + rhs.y);
  }
}

alias Point!int point;

const auto sibPoints = [point(-1, 0), point(0, -1), point(1, 0), point(0, 1)];

struct Matrix(T)
{
  import std.algorithm, std.conv, std.range, std.traits, std.typecons;

  T[][] m;
  size_t rows, cols;

  mixin Proxy!m;

  this(size_t r, size_t c) { rows = r; cols = c; m = new T[][](rows, cols); }
  this(T[][] s) { rows = s.length; cols = s[0].length; m = s; }

  auto opIndex(U)(U p) { static if (is(U == Point!V, V)) return m[p.y][p.x]; else return m[p]; }
  auto opIndex(size_t y, size_t x) { return m[y][x]; }
  static if (isAssignable!T) {
    auto opIndexAssign(U)(T v, Point!U p) { return m[p.y][p.x] = v; }
    auto opIndexAssign(T v, size_t y, size_t x) { return m[y][x] = v; }
  }
  auto validIndex(U)(Point!U p) { return p.x >= 0 && p.x < cols && p.y >= 0 && p.y < rows; }
  auto points(U)() { return rows.to!U.iota.map!(y => cols.to!U.iota.map!(x => Point!U(x, y))).joiner; }
}