#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(void) {
    int depth = 0;
    int pos = 0;
    int val;
    char comm[256];
    while(scanf("%255s %d\n", comm, &val) != EOF) {
        if (!strcmp(comm, "forward")) {
            pos += val;
        } else if (!strcmp(comm, "up")) {
            depth -= val;
        } else if (!strcmp(comm, "down")) {
            depth += val;
        } else {
            fprintf(stderr, "bad command: %s\n", comm);
            exit(1);
        }
    }
    printf("%d\n", pos * depth);
    return 0;
}