Design a program that asks for the number of fat grams and calories in a food item. Validate the input as follows:

- Make sure the number of fat grams and calories are not less than 0.

- According to nutritional formulas, the number of calories cannot exceed fat grams x 9. Make sure that the number of calories entered is not greater than fat grams x 9.

Once correct data has been entered, the program should calculate and display the percentage of calories that come from fat. Use the following formula:

Percentage of calories from fat = (fat grams x 9) / calories

Some nutritionists classify a food as "low fat" if less than 30 percent of its calories come from fat. If the results of this formulas are less than 0.3, the program should display a message indicating the food is low in fat.