#include<bits/stdc++.h> using namespace std; int n,sum,sum1,b,c; int h(int d){ sum1=0; while(d>0){ sum1+=d%10; d/=10; } return sum1; } int main(){ cin>>n; for(b=1;b<=n;b++){ c=h(b); if(c==13){ sum++; } } cout<<sum; }