Is it safe to replace Type A plug with Type C?
You need to learn to tell the difference between a plain plug and a power supply with a built-in plug (known as a wall-wart).

There are several giveaways that indicate something is a wall-wart and not a regular plug.


Wall warts are typically much larger than regular plugs.
The output cable of of a wall-wart will typically be thinner and more lightly insulated than a mains cable.
The output connectors of a wall-wart will typically be of types that are only safe for use at low voltages.
A wall-wart will typically have a label indicating input voltage range, output voltage, power requirements and safety approvals. 


Not every wall wart will have all these indications, but most will have at least one of them. 

Both of the items in your pictures are wall-warts, if you remove a wall-wart and replace it with a regular plug you will almost certainly destroy the equipment and create a serious electric shock hazard.

Russia apparently uses 220V, which is similar to most of Europe (the EU is nominally 230V but with a pretty wide tolerance band) and much higher than used in the USA. Before connecting a device with a US plug to Russian mains you need to check it is suitable for the higher voltage.

Some devices, especially older ones, may need to be reconfigured for different voltages either by moving a switch, turning an insert, moving fuses inside the device or a variety of other mechanisms. This is unlikely to be the case with wall-warts though.

The label on your wall-warts should indicate the acceptable range of input voltages, most but not all modern wall-warts will be designed with a wide input voltage range (e.g. 100-240V) that covers essentially all mains voltages in the world. If your wall-warts have a suitable input voltage range you can use them with a plug adapter, otherwise you will need to source replacement power supplies.

Unfortunately sourcing replacement power supplies can be a pain. There are a wide variety of combinations of voltage, current, output connector and sometimes even output polarity out there.