// DO NOT IMPORT THIS MORE THAN ONCE
$sides: top bottom left right;

@each $size in $spacing-sizes{
  .m-#{nth($size, 1)}{
    margin: nth($size, 2);
  }
  .p-#{nth($size, 1)}{
    padding: nth($size, 2);
  }
  @each $side in $sides{
    .m-#{$side}-#{nth($size, 1)}{
      margin-#{$side}: nth($size, 2);
    }
    .p-#{$side}-#{nth($size, 1)}{
      padding-#{$side}: nth($size, 2);
    }
  }
}