Unsure of your term "inputs". To construct a nuclear weapon, it requires a source of scarce fissionable materials, such as Uranium 235, or Plutonium. It requires the ability to perform precision machining of these VERY difficult to work with materials. It requires the use of precisely shaped high explosives of assorted types, the use of extremely high precision electronic timing equipment used to detonate the high explosive trigger, and a source of metals for a neutron donor ( such as beryllium) and the ability to machine that. Along the way, it is good not to die from handling and machining the metals. You also need a way to deliver a very heavy package- the original atomic bombs weighed 9000 to 10,000 lbs.
The scientist given the most credit for the building of the atomic bomb is Robert Oppenheimer.
The Manhattan project
It was code named Manhattan Project.
Robert Oppenheimer
No. By the time the US dropped the atomic bomb on Japan, Germany had already surrendered. While Germany did have a nuclear weapons program during the war, it did not actually get to the point that they were capable of building a working bomb.
Oppenheimer......................
The Manhattan Project
Building the first atomic bomb.
Robert Oppenheimer
Their project to build an atomic bomb started before the US, but because of several mistakes in experiments and calculations the priority was lowered and the project redirected to only building power reactors after the war.
The fear that Germany was already well on the way to building an atomic bomb and could make first use of them against either England or the USSR at any moment.
how was the atomic bomb repaired