import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class day02Part2 {
	public static void main(String[] args) throws IOException {
		int posHorizontal = 0;
		int posDepth = 0;
		int aim = 0;
		int finalAns = 0; // posHorizontal * posDepth

		String line;

		String direction;
		int movement;

		BufferedReader in = new BufferedReader(new FileReader("day02-input.txt"));
		line = in.readLine();
		while (line != null) {

			String[] lineProcess = line.split(" ");
			
			direction = lineProcess[0];
			movement = Integer.valueOf(lineProcess[1]).intValue();

			if (direction.compareTo("forward") == 0) {
				int temp = 0;

				posHorizontal += movement;

				temp = movement * aim;
				posDepth += temp;
			}
			else if (direction.compareTo("up") == 0) {
				// posDepth -= movement;
				aim -= movement;
				
			}
			else if (direction.compareTo("down") == 0) {
				// posDepth += movement;
				aim += movement;
			}

			line = in.readLine();
		}

		in.close();

		finalAns = posHorizontal * posDepth;
		System.out.println(finalAns);
	}

}