#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,i,b,c,d,a=1,h=0;
	cin>>n;
	for(a=1;a<=n;a+1){
		i=a%10;
		b=a/10%10;
		c=a/100%10;
		d=a/1000;
		if(i%2==0||i%5==0||b%2==0||b%5==0||c%2==0||c%5==0||d%2==0||d%5==0){
			h++;
		}
	}cout<<h;



    return 0;
}

/**************************************************************
	Problem: 1395
	User: caiqiaoxi
	Language: C++
	Result: Time Limit Exceed
****************************************************************/