a = int(input()) shuchu = 0

if a >= 401: shuchu = (a-400) * 0.5663 + 116.575 + 66.945

elif a >= 151: shuchu = (a-150) * 0.4663 + 66.945

else: shuchu = a * 0.4463

shuchu = round(shuchu, 1) print(shuchu)