A connection between force and potential energy

Some people, each of mass m = 50 kg, walk around a construction site. What is the gravitational potential energy of a person standing at each location?

location              GPE 
------------------------------
   A        
   B
 
   C
   E

   F
   G
------------------------------

Suppose that a person walks from one location to another. How does his GPE change? What is the component of the gravitational force acting with (+) or against (-) his motion?

                   change in   component of grav
from       to       GPE (J)       force (N)
----------------------------------------------------
  B        C
 
  E        F

  C        E
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