float offset(String section)
    {
       int H,W,t;
       float area,static_moment;

       String[] size = section.split("[\\D]+");
       for(int i=1;i<=3;i++){
          System.out.println(size[i]);
       }
       H = Integer.parseInt(size[1]);
       W = Integer.parseInt(size[2]);
       t = Integer.parseInt(size[3]);
       area = (H-t)*t + W*t;
       static_moment = (float) ((H-t)*t*(H-t)/2.0 + W*t*(H-t/2.0));
        if(area==0){
            return -1;
        }
       return static_moment/area;
    }