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: Wrong Answer)

var
  n,i,j,m,ans:longint;
  s:string;
  b1,b2,b3:boolean;
begin
  readln(n);
  if n<357 then begin writeln('0'); halt; end;
  if (1000<n)and(n<=10000) then begin ans:=6; m:=1000; end;
  if (10000<n)and(n<=100000) then begin ans:=42; i:=10000; end;
  if (100000<n)and(n<=1000000) then begin ans:=192; i:=100000; end;
  if (1000000<n)and(n<=10000000) then begin ans:=732; i:=1000000; end;
  if (10000000<n)and(n<=100000000) then begin ans:=2538; i:=10000000; end;
  if (100000000<n)and(n<=1000000000) then begin ans:=8334; i:=100000000; end;
  if (333333357<=n)and(n<=1000000000) then begin writeln('26484'); halt; end;
  if (750000<n)and(n<=7500000) then begin ans:=617; i:=750000; end;
  if (7500000<n)and(n<=75000000) then begin ans:=2147; i:=7500000; end;
  if (33500000<n)and(n<=335000000) then begin ans:=2718; i:=33500000; end;
  if (335000000<n)and(n<=3350000000) then begin ans:=8936; i:=335000000; end;

  for i:=m 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.