kwh = 500
moeny = 0

if kwh <= 200:
    moeny =  kwh * 100
elif kwh <= 400:
    moeny = 200 * 100 + (kwh - 200) * 200
else:
    moeny = 200 * 100 + 200 * 200 + (kwh - 400) * 300

print(moeny)