#include<stdio.h>

int fun(int n){
	int r=0;
	while(n!=0){
		r=r+n%10;
		n=n/10;
	}
	return r;
}

void main(){
	int n,i,c=0;
	scanf("%d",&n);
	for(i=1;i<=n;i++){
		if(fun(i)==13){
			c++;
		}
	}
	printf("%d",c);
}
/**************************************************************
	Problem: 1511
	User: admin
	Language: C
	Result: Accepted
	Time:107 ms
	Memory:1144 kb
****************************************************************/