':type costs: List[List[int]]
:rtype: int'

def minCost(self, costs):

    if (not costs):
        return 0
    n = len(costs)
    for i in xrange(1, n):
        costs[i][0] += min(costs[(i - 1)][1], costs[(i - 1)][2])
        costs[i][1] += min(costs[(i - 1)][0], costs[(i - 1)][2])
        costs[i][2] += min(costs[(i - 1)][0], costs[(i - 1)][1])
    return min(costs[(n - 1)])
