int main()
{
      Node node;
      int i, j;
      int total = 0;
      int cho = 0;
      int array1[1000];
      int array2[1000];
      Stack *s = makeStack();
      FILE *f = fopen("expreval.txt", "r");
      if (f == NULL)
            printf("FILE ERROR\n");
      else
      {
            fscanf(f, "%d", &n);
            for (i = 1; i <= n; i++)
            {
                  fscanf(f, "%d", &array1[i]);
            }
            for (j = 1; j < n; j++)
            {
                  fscanf(f, "%d", &array2[j]);
            }
      }
      for (i = 1; i <= n; i++)
            for (j = 1; j < n; j++)
            {
                  pushStack(s, array1[i]);
                 if(array2[j] == 2)
                 {
                       cho = topStack(s);
                       popStack(s);
                       cho = cho*array1[i];
                       pushStack(s, cho);
                 }
            }
      for(j = n-1; j >= 1; j--)
      {
            total = total + topStack(s);
            if(array2[j] == 0)
            total = total - topStack(s);
            if(array2[j] == 1)
            total = total + topStack(s);
            if(array2[j] == 2)
            total = total + topStack(s);
      }
      printf("%d\n", total);
      return 0;
}