def fval_function(sN, weight):
    # IMPLEMENT
    """
    Provide a custom formula for f-value computation for Anytime Weighted A star.
    Returns the fval of the state contained in the sNode.

    @param sNode sN: A search node (containing a SokobanState)
    @param float weight: Weight given by Anytime Weighted A star
    @rtype: float
    """
    fval = sN.gval + weight * sN.hval
    return fval