code: def make_inst1():
      
      I,d = multidict({1:80, 2:270, 3:250 , 4:160, 5:180}) # demand
      J,M = multidict({1:500, 2:500, 3:500})               # capacity
      c = {(1,1):4,    (1,2):6,    (1,3):9,  # cost
           (2,1):5,    (2,2):4,    (2,3):7,
           (3,1):6,    (3,2):3,    (3,3):4,
           (4,1):8,    (4,2):5,    (4,3):3,
           (5,1):10,   (5,2):8,    (5,3):4,
           }
      return I,J,c,d,M
docs: creates example data set 1