indices_biggest: This function returns a list containing the indices of the largest value in its sole argument, a nonempty matrix, i.e. [row index, col index]. If there is only one element in the matrix, return [0, 0]. If there are multiples of the same max value, return the first occurrence going from left to right and then down the matrix. second_biggest: This function returns the second largest value in its sole argument, a matrix containing at least two elements. If the largest value occurs more than once, it counts as the second largest also