#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	int cnt=0;
	for(int x=1;x<=n;x++)
	{
		int cnt1=0,cnt2=0;
		int t=x;
		while(t)
		{
			int ge=t%10;
			if(ge==7) cnt1++;
			t/=10;
		}
		t=x;
		while(t)
		{
			int ge=t%8;
			if(ge==7) cnt2++;
			t/=8;
		}
		if(cnt1==0&&cnt2==0)
		{
			cnt++;
		}
	}
	cout<<cnt;
	return 0;
}