input: def linear_eq(a: int, b: int, c: int) -> int:
      """ This function calculates the objective value of a linear equation ax + by = c
      where x and y are defined in the context of the problem. The output depends on the 
      selected values for x and y.
      >>> linear_eq(3, 5, 7)  # Assuming x=1 and y=2
      6
      >>> linear_eq(2, -3, 1)  # Assuming x=2 and y=1
      -5
      """
output:     x = 1
      y = 2
      return a * x + b * y