import os

dir = os.path.dirname(os.path.abspath(__file__))

with open(os.path.join(dir, './input.txt'), 'r') as input_file:

    lines = input_file.readlines()

    horizontal = 0
    depth = 0

    for line in lines:
        parts = line.split(' ')
        command = parts[0]
        distance = int(parts[1])
        if command == 'forward':
            horizontal = horizontal + distance
        elif command == 'up':
            depth = depth - distance
        elif command == 'down':
            depth = depth + distance

    print(horizontal*depth)