#include<bits/stdc++.h>
using namespace std;
int main(){
	int i=1,h=0,n,m=0,j=0;
	cin>>n;
	while(i<=n){
		h=0;
		j=i;
		while(j>0){
			h=h+j%10;
			j=j/10;
		}
		if(h==10){
			m=m+1;
		}
		i++;
	}	
	cout<<m;
	return 0;
}

/**************************************************************
	Problem: 1985
	User: miaozeyu
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/