Categorize the input news's emotional tone into one of three groups.
Options: positive, negative

The growth of Amazon's air cargo fleet and the number of daily flights has slowed in recent months, except at its Northern Kentucky hub and a few other geographic pockets. That reflects the mega-retailer's more cautious approach to expansion in line with a recent pullback in warehouses because of decelerating e-commerce demand, according to research released Tuesday.
negative