from ortools.linear_solver.pywraplp import Solver

solver = Solver('basic LP', Solver.GLOP_LINEAR_PROGRAMMING)

r = solver.NumVar(0, Solver.Infinity(), 'r')
p = solver.NumVar(0, Solver.Infinity(), 'p')
c = solver.NumVar(0, Solver.Infinity(), 'c')

# adding/scalar multiplying variables gives an **expression**
calories = 750*r + 1200*p + 1000*c
# an expression coupled with an (in)equality gives a **constraint**
calorie_constraint = (calories >= 5000)

solver.Add(calorie_constraint)
solver.Add(
    15*r + 35*p + 60*c <= 200
)
solver.Minimize(
    1.25*r + 1.65*p + 1.35*c
)

if solver.Solve() == Solver.OPTIMAL:
    print(f'r={r.solution_value()}, p={p.solution_value()}, c={c.solution_value()}')
    print(f'calories={calories.solution_value()}')
else:
    print('Not possible')