.asirem-border-radius(@elem) {
  &:nth-child(2n) {
    @{elem} {
      border-radius: @asirem-border-radius-a;
    }
  }

  &:nth-child(2n+1) {
    @{elem} {
      border-radius: @asirem-border-radius-b;
    }
  }

  &:nth-child(3n) {
    @{elem} {
      border-radius: @asirem-border-radius-c;
    }
  }
}