chain matrix multiplication using dynamic programming

def mul(arr, n): 
    m = [[0 for x in range(n)] for x in range(n)] 
    for i in range(1, n): 
        m[i][i] = 0
    for L in range(2, n): 
        for i in range(1, n - L + 1): 
            j = i + L - 1
            m[i][j] = sys.maxsize 
            for k in range(i, j): 
                q = m[i][k] + m[k + 1][j] + arr[i - 1] * arr[k] * arr[j] 
                if q < m[i][j]: 
                    m[i][j] = q 
    return m[1][n - 1]