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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <string.h>

#define REP(i, n) for (int i = 0; i < n; ++i)
#define INF 9999999999999999


#define ll long long

int n, c = 0;

void dfs(ll i,int t,int f,int s) {
	if (i > n) return;
	if (t && f && s && i!=n) ++c;
	dfs(i*10+3,t+1,f,s),
	dfs(i*10+5,t,f+1,s),
	dfs(i*10+7,t,f,s+1);
}


int main() {
	scanf("%lld", &n);
	dfs(0,0,0,0),

	printf("%lld\n", c);
	return 0;
}