#include <iostream>
#include <stdlib.h>

using namespace std;

int main()
{
    string input;
    const string forward = "forward";
    const string up = "up";
    const string down = "down";
    int horizontal = 0;
    int depth = 0;
    int aim = 0;
    
    while(getline(cin,input))
    {
        int amount = atoi(&input.c_str()[input.find(' ')]);;
        
        if (string::npos != input.find(forward))
        {
            horizontal += amount;
            depth += amount*aim;
        }
        else if (string::npos != input.find(up))
        {
            aim -= amount;
        }
        else if (string::npos != input.find(down))
        {
            aim += amount;
        }
    }

    cout << horizontal*depth << endl;

    return 0;
}