189

x=input()
while x!="":
    x=int(x)
    if x>0 and x<=10:
        print(6*x)
    if x>=11 and x<=20:
        print(60+2*(x-10))
    if x>=21 and x<40:
        print(80+x-20)
    if x>=40:
        print(100)
    x=input()