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