import sys

total_premium = 0
ncars = 0

oldest_age = 0
highest_class = 0
lowest_class = 1000

with open(sys.argv[1]) as f:

    for line in lines[1:]:
        words = line.split(",")

        if len(words) >= 4:
            make = words[0]
            car_class = int( words[1] )
            premium = float( words[2] )
            age = float( words[3] )

            ncars += 1

            total_premium += premium

            if age > oldest_age:
                oldest_make = make
                oldest_age = age

            if car_class > highest_class:
                highest_make = make
                highest_class = car_class
    
            if car_class < lowest_class:
                lowest_make = make
                lowest_class = car_class
 
avg_premium = total_premium / ncars

print("The average premium is $%s." % avg_premium)
print("The oldest make is %s." % oldest_make)
print("The make in the lowest class is %s." % lowest_make)
print("The make in the highest class is %s." % highest_make)