use std::env::args;
use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;

fn main() {
    let path = args().nth(1).unwrap();
    let file = File::open(path).unwrap();

    let mut x = 0;
    let mut y = 0;
    let mut aim = 0;

    for line in BufReader::new(file).lines() {
        let l = line.unwrap();
        let i = l.find(' ').unwrap();
        let dir = &l[..i];
        let k = &l[i+1..].parse::<i32>().unwrap();

        match dir {
            "down" => aim += k,
            "up" => aim -= k,
            "forward" => {
                x += k;
                y += k * aim;
            },
            _ => panic!("invalid direction"),
        }
    }
    print!("{}\n", x * y);
}