#include<bits/stdc++.h>
using namespace std;
int main(){
int i,n,g,s,b,h=0;
	cin>>n; 
	for(i=1;i<=n;i++){
		g=i%10;
		s=i/10%10;
		b=i/100;
		if(g+s+b==10){
			h++;
		}
	}
	cout<<h<<endl;
	return 0;
}
/**************************************************************
	Problem: 1985
	User: xiaojingxuan
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/