Flexbox - How to do space-around in vertical?

Question

Probably it's a noob question, but I'm wondering how it's possible do something similar "space-around" but in vertical direction.

This: Half-pad Element pad Element pad Element half-pad

This:
Half-pad
Element
pad
Element
pad
Element
half-pad

I'm missing how to do half-pad too.

Doing direction: vertical misses initial and end space-around.

.stabled {
  position: fixed;
  right:0px;
  top:0;
  width:15px;
  height:100%;
  z-index:95;
  opacity: 0.6;
  filter: alpha(opacity=60); /* For IE8 and earlier */
   
  -webkit-transition: all 1s ease;
	-moz-transition: all 1s ease;
	-o-transition: all 1s ease;
	-ms-transition: all 1s ease;
	transition: all 1s ease;
}

.stabled ul {
	position:relative;
	display: -webkit-box;
  	display: -moz-box;
  	display: -ms-flexbox;
  	display: -webkit-flex;
  	display: flex;
	
	-webkit-flex-direction:column;
	flex-direction:column;
	
	height:100%;
	width:170px;
}


nav.stabled ul li {
	position:relative;
	float:left;
	margin: 0 auto;
	}
	
	
.stabled li.firl {
	padding-left:0;
	padding-top:35px;
	}


.stabled:hover {
  position: fixed;
  width:170px;
  box-shadow: 0 0 10px #222;
  -webkit-box-shadow: 0 0 40px #222;
  -moz-box-shadow: 0 0 40px #222;
  opacity: 1;
  filter: alpha(opacity=100); /* For IE8 and earlier */
}

Solution

Resolved. It was a different mistake because image sizes. Solution is simple: codepen.io/devtips/pen/OPQYav (Made by youtube.com/user/DevTipsForDesigners)

.parent {
  border: 3px solid orange;
  height: 400px;
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
}

.child {
  width: 100px;
  height: 100px;
  background: blueviolet
}

<div class="parent">
  <div class="child"></div>
  <div class="child"></div>
  <div class="child"></div>
</div>