from collections import deque

def heat_spread(grid):
    n = len(grid)
    m = len(grid[0])
    new_grid = [row[:] for row in grid]
    directions = [(-1,0), (1,0), (0,-1), (0,1)]

    for i in range(n):
        for j in range(m):
            if grid[i][j] == 'H':
                for dx, dy in directions:
                    ni, nj = i + dx, j + dy
                    if 0 <= ni < n and 0 <= nj < m and grid[ni][nj] == '.':
                        new_grid[ni][nj] = 'H'
    return new_grid

def simulate_heat(grid, start_x, start_y, end_x, end_y):
    n = len(grid)
    m = len(grid[0])
    queue = deque()
    visited = set()
    queue.append((start_x, start_y, 0, grid))
    visited.add((start_x, start_y))

    while queue:
        x, y, days, curr_grid = queue.popleft()
        if (x, y) == (end_x, end_y):
            return days

        next_grid = heat_spread(curr_grid)
        directions = [(-1,0), (1,0), (0,-1), (0,1)]

        for dx, dy in directions:
            nx, ny = x + dx, y + dy
            if 0 <= nx < n and 0 <= ny < m and next_grid[nx][ny] == '.' and (nx, ny) not in visited:
                visited.add((nx, ny))
                queue.append((nx, ny, days + 1, next_grid))
    return -1

# Input Format
n = int(input())
grid = []
for _ in range(n):
    grid.append(list(input().strip()))

start_x, start_y = map(int, input().split())
end_x, end_y = map(int, input().split())

print(simulate_heat(grid, start_x, start_y, end_x, end_y))