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 Pascal (FPC 2.6.2) (judge verdict: Time Limit Exceeded)

var
  a,b,c,i,j,ans,m:longint;
  n:int64;
  s,s2:string;
  b1,b2,b3:boolean;
begin
  readln(n);
  for i:=1 to n do
  begin
    b1:=false;
    b2:=false;
    b3:=false;
    s:='';
	str(i,s);
    s:=s+'4';
    for j:=1 to length(s) do 
    begin 
      if (s[j]<>'3')and(s[j]<>'5')and(s[j]<>'7') then break;
      if s[j]='3' then b1:=true;
      if s[j]='5' then b2:=true;
      if s[j]='7' then b3:=true;
    end;
    if b1 and b2 and b3 and(j=length(s)) then inc(ans);
  end;
  writeln(ans);
end.