#The person is purchasing apples and apple pies in the store. Write the 
#program that reads the number of pounds and price per pound for apples, 
#the number of pies and price of one pie, and the tax (integer). The 
#program finds and prints the total purchase price. For example, if the 
#person purchased 3 pounds of apples, 1.99 per pound, and 2 apple pies, 
#7.99 each, and the tax is 6%, the total purchase price is: 23.27 dollars. 

#Discussion
#Input: apple_pound (float), apple_price (float), num_pie (int), pie_price 
#(float), tax (int). Limitations: all prices>0, apple_pound>=0, 
#num_pie>=0, tax>=0

#Calculations: total=(apple_pound*apple_price + num_pie*pie_price)*(1+tax/100)
#The longer formula will be: apple_pound*apple_price + num_pie*pie_price + 
#(apple_pound*apple_price + num_pie*pie_price)*tax/100
#Using the rule: a*(b+c)=a*b+a*c

#Output: total - float, limitation, total>=0

#Input
apple_pound=float(input("enter number of pounds "))
apple_price=float(input("enter price of apples per pound "))
num_pie=int(input("enter number of pies "))
pie_price=float(input("enter price of pie "))
tax=int(input("enter tax as an integer percent "))

#Calculations and Outputs

#Step 1 - validity of the input

validity = apple_pound>=0 and apple_price>0 and num_pie>=0 and pie_price>0 and tax>=0

if(validity == True):
	total=(apple_pound*apple_price + num_pie*pie_price)*(1+tax/100)
	print("total amount is",format(total, '.2f'))	
else:
	print("invalid input")