$spacings: (
  "xxs": 4,
  "xs": 8,
  "s": 12,
  "m": 20,
  "l": 32,
  "xl": 52,
  "xxl": 84
);
$sides: (top, bottom, left, right);

@each $spacingName, $spacingAmount in $spacings {
  @each $side in $sides {
    .m-#{str-slice($side, 0, 1)}-#{$spacingName} {
      margin-#{$side}: #{$spacingAmount}px !important;
    }

    .p-#{str-slice($side, 0, 1)}-#{$spacingName} {
      padding-#{$side}: #{$spacingAmount}px !important;
    }
  }
}