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


/**************************************************************
	Problem: 1511
	User: linzihang
	Language: C++
	Result: Accepted
	Time:109 ms
	Memory:2072 kb
****************************************************************/