math, physic, russian = 0, 0, 0 ; counter = 0 ; output = open('output.txt', 'w')
with open('dataset_3363_4.txt') as text:
    for lines in text:
        middle = text.readline().strip().split(';')
        a, b, c = int(middle[1]), int(middle[2]), int(middle[3])
        print(( a + b + c)/3, middle, file = output)
        counter += 1
        math += a ; physic += b ; russian += c
print((math/counter), (physic/counter), (russian/counter), file = output)
output.close()