~~~

x = float(input())
s = 0
if x >= 0:
if x > 2000.00:
if x > 3000:
s = 80
if x > 3000.00:
if x > 4500:
s += 270
s += (x - 4500) *0.28
else:
s += (x - 3000.00) * 0.18
else:
s = (x - 2000.00) * 0.08
print(“R$ %.2lf”%s)
else:
print(“Isento”)

~~~