Problem:
Score : 300 points

Problem Statement

You are given an integer N. Among the integers between 1 and N (inclusive), how many Shichi-Go-San numbers (literally "Seven-Five-Three numbers") are there?

Here, a Shichi-Go-San number is a positive integer that satisfies the following condition:

When the number is written in base ten, each of the digits 7, 5 and 3 appears at least once, and the other digits never appear.

Constraints

1 \leq N < 10^9

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the number of the Shichi-Go-San numbers between 1 and N (inclusive).

Sample Input 1

575

Sample Output 1

4

There are four Shichi-Go-San numbers not greater than 575: 357, 375, 537 and 573.

Sample Input 2

3600

Sample Output 2

13

There are 13 Shichi-Go-San numbers not greater than 3600: the above four numbers, 735, 753, 3357, 3375, 3537, 3557, 3573, 3575 and 3577.

Sample Input 3

999999999

Sample Output 3

26484

Solution in Lua (LuaJIT 2.1.0) (judge verdict: Accepted)

local n=io.read("n")
local t={3,5,7}
local i=1
while t[#t]<=n do
    for j=3,7,2 do
        t[#t+1]=t[i]*10+j
    end
    i=i+1
end
local counter=0
for i=1,#t do
    local three=false
    local five=false
    local seven=false
    local copy=t[i]
    while copy>0 do
        if copy%10==3 then three=true
        elseif copy%10==5 then five=true
        elseif copy%10==7 then seven=true
        end
        copy=math.floor(copy/10)
    end
    if three and five and seven and t[i]<=n then
        counter=counter+1
    end
end
print(counter)