The old King Neptune had given away parts of his undersea empire in his will. The following assets were to be divided among his three daughters, Ariel, Muriel, and Unriel: 7 million seashells, 1 coral reef villa worth 5 million seashells, 3 shipwreck motels each worth 3 million seashells, and a number of diamonds, each worth a hundred thousand seashells. He wanted each child to get an equal share, with the condition that the villa, motels, and diamonds were not to be split further, and would be inherited by a princess as a unit each. Among the princesses, Ariel received the least amount in seashells while Unriel received the highest. The other assets were divided equally among them, as were the diamonds. How many shipwreck motels did Ariel inherit?