#include<bits/stdc++.h>
using namespace std;
int main() {
	int i,n,g,s,b,q,c = 0;
	cin>>n;
	for(i = 1;i <= n;i++){
		q = i / 1000;
		b = i / 100 % 10;
		s = i / 10 % 10;
		g = i % 10;
		
		if(q == 8){
			c++;
		}
		
		if(b == 8){
			c++;
		}
		
		if(s == 8){
			c++;
		}
		
		if(g == 8){
			c++;
		}
	}
	
	cout<<c;
	return 0;
}
/**************************************************************
	Problem: 1987
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/