Criteria for an amphibious aircraft

The main operational requirements for amphibious aircraft being developed for hard-to-reach areas:

Amphibious: must perform takeoffs and landings from both land-based airfields and from the water surface, as well as from ice runways.
It must have a shortened takeoff and landing in a limited space.
In accordance with the rules of operation of aircraft in terms of range and passenger capacity, it must have two engines.