n=input()
def wow(n):
    if len(n)<3:
        count=0
        for i in range(10,100):
            if i%3==0:
                count+=1
        print(count)
        exit()
    ans=0
    nl=len(n)
    for i in range(2,nl-1):
        ans+=3*(4**i)
    if int(n[0])%3!=0:
        return((int(n[0])//3+1)*ans+30)
    else:
        return (int(n[0])//3)*ans+wow[n[1:]]
print(wow(n))