#include<bits/stdc++.h>
using namespace std;
int main() {
	int n,c = 0,g,s,b;
	cin>>n;
	for(int i = 1;i <= n;i++){
		b = i / 100;
		s = i / 10 % 10;
		g = i % 10;
		
		if(b + s + g == 10){
			c++;
		}
	}
	
	cout<<c;
	return 0;
}
/**************************************************************
	Problem: 1985
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/