HP

def initMatrix(l, c, val):
    M = []
    for i in range(l):
        M.append([])
        for j in range(c):
            M[i].append(val)
    return(M)


def BuildMaxMat(T):
    l = len(T)
    c = len(T[0])
    M = initMatrix(l, c, 0)
    for j in range(c):
        M[0][j] = T[0][j]
    for i in range(1, l):
        M[i][0] = T[i][0] + max(M[i - 1][0], M[i - 1][1])
        for j in range(1, c - 1):
            M[i][j] = T[i][j] + max(M[i - 1][j - 1], M[i - 1][j], M[i - 1][j + 1])
        M[i][c - 1] = T[i][c - 1] + max(M[i - 1][c - 2], M[i - 1][c - 1])
    return M


def maxList(L):
    m = 0
    for i in range(1, len(L)):
        if L[i] > L[m]:
            m = i
    return m


def harryPotter(T):
    """Computes maximum number of philosopher stones Harry can get.

    Uses dynamic programming strategy
    """
    M = BuildMaxMat(T)
    n = len(M)
    return M[n - 1][maxList(M[n - 1])]