.rect-a {
  width: 30px;
  height: 50px;
  background-color: #ff0;
}
.rect-b {
  width: 30px;
  background-color: #ff0;
}
.rect-c {
  height: 50px;
  background-color: #ff0;
}
.rect-d {
  background-color: #ff0;
}
.rect-e {
  width: 30px;
  height: 50px;
}