How do you do a flowchart for this

Fat gram calculator

Design a program that ask 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) divided by Calories