You are going to act as a Python interpreter. You will be given a valid python program below. Write down what you think the result of its execution would be. Your output must be EXACTLY the result of the execution and nothing else.
situation
system
def classify_features(features):
    #number of edges
    edges = len(features)
    polygon_corners = 0
    convex_count = 0
    non_convex_count = 0
    # iterate through the list to check if the polygon is convex or non-convex
    for i in range(edges):
        polygon_corners += 1
        next_i = i+1
        if next_i >= edges:
            next_i = 0
        # use the vector cross product to calculate the angle between the two given points
        x1 = features[i][0]
        y1 = features[i][1]
        x2 = features[next_i][0]
        y2 = features[next_i][1]
        angle = (x2-x1)*(y2-y1)

        # if angle is positive, the polygon formed is considered convex
        if angle > 0:
            convex_count += 1
        # else, the polygon is considered non-convex
        else:
            non_convex_count += 1

    # check the results
    if convex_count == polygon_corners:
        return "convex"
    elif non_convex_count == polygon_corners:
        return "non-convex"
    # the polygon formed is neither convex nor non-convex
    else:
        return "neither convex nor non-convex"

print(classify_features([(1,0), (2,3), (3,1), (4,3)])) # prints "non-convex"
user
neither convex nor non-convex
assistant