import queue
from collections import namedtuple

dx = (1, 0, -1, 0)
dy = (0, -1, 0, 1)
Point = namedtuple('Point', 'x y')

def solve():
    n, v, sx, sy, gx, gy = [int(i) for i in input().split(' ')]
    start = Point(x = sx-1, y = sy-1)
    goal = Point(x = gx-1, y = gy-1)
    costs = [[int(i) for i in input().split(' ')] for _ in range(n)]
    mincosts = [[v for _ in range(n)] for _ in range(n)]
    mincosts[start.y][start.x] = 0
    q = queue.Queue()
    in_queue = [[False for _ in range(n)] for _ in range(n)]
    q.put(start)
    in_queue[start.y][start.x] = True
    cnt = 0
    while True:
        tmp = queue.Queue()
        if q.empty() or mincosts[goal.y][goal.x] < v:
            break
        while not q.empty():
            x, y = q.get()
            in_queue[y][x] = False
            for tx, ty in zip(dx, dy):
                nx = x + tx
                ny = y + ty
                if nx >= 0 and nx < n and ny >= 0 and ny < n:
                    tmpcost = mincosts[y][x] + costs[ny][nx]
                    if mincosts[ny][nx] > tmpcost:
                        mincosts[ny][nx] = tmpcost
                        if not in_queue[ny][nx]:
                            tmp.put(Point(nx, ny))
                            in_queue[ny][nx] = True
                        
        q = tmp
        cnt += 1
        
    if mincosts[goal.y][goal.x] < v:
        print(cnt)
    else:
        print(-1)

if __name__ == "__main__":
    solve()