from collections import deque
def minimumMoves(grid, startX, startY, goalX, goalY):
    # Note: 
    # X means vertical direction in problem description's diagram
    # Y means horizontal direction in problem descritions's diagram
    # This is different with our habit. 
    # So I don't use the word left, right, up, or down in my code to avoid misleading names
    
    len_X = len(grid)
    len_Y = len(grid[0])
    visited = []
    for i in range(len_X):
        visited.append([False]*len_Y)
    
    queue = deque()
    # In the queue, each element is a tuple
    # Each tuple has 3 elements: x, y, and the number of moves from starting point to this location
    queue.append((startX, startY, 0))
    visited[startX][startY] = True
    while queue:
        cur_x, cur_y, cur_d = queue.popleft()
        
        if cur_x == goalX and cur_y == goalY:
            return cur_d
        
        #Add all potential moves toward smaller X
        for x in range(cur_x)[::-1]:
            if grid[x][cur_y] == '.' and not visited[x][cur_y]:
                queue.append((x,cur_y,cur_d+1))
                visited[x][cur_y] = True
            elif grid[x][cur_y] == 'X':
                break
                
        #Add all potential moves toward bigger X
        for x in range(cur_x,len_X):
            if grid[x][cur_y] == '.' and not visited[x][cur_y]:
                queue.append((x,cur_y,cur_d+1))
                visited[x][cur_y] = True
            elif grid[x][cur_y] == 'X':
                break
                
        #Add all potential moves toward smaller Y
        for y in range(cur_y)[::-1]:
            if grid[cur_x][y] == '.' and not visited[cur_x][y]:
                queue.append((cur_x,y,cur_d+1))
                visited[cur_x][y] = True
            elif grid[cur_x][y] == 'X':
                break
                
        #Add all potential moves toward bigger Y
        for y in range(cur_y,len_Y):
            if grid[cur_x][y] == '.' and not visited[cur_x][y]:
                queue.append((cur_x,y,cur_d+1))
                visited[cur_x][y] = True
            elif grid[cur_x][y] == 'X':
                break
    return -1   # The flag when the goal is not reachable