import shared


class Position:
    def __init__(self):
        self.horiz = 0
        self.depth = 0
        self.aim = 0

    def parse_line(self, line: str):
        direction, x = line.split(" ")
        x = int(x)

        if direction == "up":
            self.aim -= x
        elif direction == "down":
            self.aim += x
        elif direction == "forward":
            self.horiz += x
            self.depth += self.aim * x

    def whereami(self):
        return self.horiz * self.depth


def run(inp):
    p = Position()
    for i in inp:
        p.parse_line(i)
    return p.whereami()


def main():
    with open(shared.get_fname(2), "r") as f:
        inp = f.readlines()

    print(run(inp))


if __name__ == "__main__":
    main()