If you have any electronics from the United States, you'll need to pick up a cord / outlet adaptor for use in Ukraine. These are easy to find in many underground passageways adjacent to metro stations.
Here is a sampling of the adaptors available:
You'll want to get only the one on the left. The others all have smaller prong diameters and will wiggle around in the outlet, giving you an unstable power connection. You'll come to hate them (trust me). I don't know what they are for if they work so poorly.
The one on the left fits snugly in any outlet and costs approximately 12 UAH.