Hi,
Why my answer in this quiz is displaying as "incorrect" whereas code is displaying right result. Can anyone help ? Answer of quiz should be [11,4,5].. and I am getting same answer . what should I do to make it displayed as"correct" after submitting it?

def check_goal(node):
    if (node[0] == goal[0]) and (node[1]==goal[1]):
        return True
def Add(delta,node):
    neighbor = []
    for i in range(len(delta)):
      x = node[0] + delta[i][0]
      y = node[1] + delta[i][1]
      if(x>=0 and x<len(grid)and(y>=0 and y<len(grid[0]))):
          neighbor.append([x,y])
    return neighbor
def search():
    g = 0
    x = init[0]
    y = init[1]
    closed = []
    opened = [[g,x,y]]
    found = False
    resign = False
    while (found is False) and (resign is False):
        if (len(opened)==0):
            resign= True
            print "Fail to complete search"
        else:
            opened.sort()
            opened.reverse()
            nextt = opened.pop()
            g = nextt[0]
            x = nextt[1]
            y = nextt[2]
            node = [x,y]
            if (check_goal(node)):
                found = True
                print nextt
            else:
                n = Add(delta,node)
                g = g+cost
                for i in range(len(n)):
                    x2 = n[i][0]
                    y2 = n[i][1]
                    if (n[i] not in closed)and(grid[x2][y2]==0):
                        opened.append([g,x2,y2])
            closed.append([x,y])
    return found

print search()