Marsha Mellow is very flexible. She consumes x and y. She says `Give me x or give me y; I don't care. I can't tell the difference between them.' She is currently endowed with 14 units of x and 6 units of y. The price of x is 4 times the price of y. Marsha can trade x and y at the going prices, but has no other source of income. How many units of y will Marsha consume?