repeated items in a loop

When you have 3 images for a grid ^^

.container
  .row
    - for (var i=0; i < 9; i++){
      .col-xs-4
        h3="images/product-"+(i%3+1)+".jpg"
        hr
    - }

Yields:

1 | 2 | 3
1 | 2 | 3
1 | 2 | 3

http://codepen.io/zsitro/pen/bEOVVd?editors=1000