def class_decision(x):
    """
    Returns a vector containing the class with the highest value (probability)
    Inverse of one_hot function

    Parameters
     - x: t.tensor, size=[n, n_classes], where each element represents the probability of the class.

    Returns t.tensor, size=[n], dtype=long, integer values in range [0, n_classes)
    """
    return x.argmax(axis=1)