#include<bits/stdc++.h>
using namespace std;
int zhai(int q){
	int s=0;
	while(q!=0){
		s+=q%10;
		q/=10;
	}
	return s;
}
int main()
{
	
	int i,n,s=0;
	cin>>n;
	for(i=1;i<n;i++){
		if(zhai(i)==13){
			s++;
		}
	} 
	cout<<s;
return 0;

}

/**************************************************************
	Problem: 1511
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:103 ms
	Memory:2072 kb
****************************************************************/