import torch


def predict(model, features):
    """
    This function evaluates a trained neural network on a validation set or a testing set.

    Inputs:
      model:            trained neural network.
      features:         the features of the testing images .

    Output:
      prediction:       the prediction of the model.
    """
    output = model(features)
    prediction = torch.argmax(output, dim=1)

    return prediction