#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define mod99 998244353
#define mod107 1000000007
#define endl "\n"
#define rep(i,n) for (ll i = 0; i < (ll)(n); ++i)
#define prep(i,a,n) for (ll i = a; i < n; ++i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(), a.rend()
#define si(x) ((ll)(x).size())
#define yn(bool) if(bool){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}
#define PRE(x) cout << fixed << setprecision(x)
#define yes cout << "Yes\n"
#define no cout << "No\n"
template <typename T> inline T gcd(T a,T b) {return (b==0)?a:gcd(b,a%b);}
template <typename T> inline T lcm(T a, T b) {return a/gcd(a,b)*b;}
#define sq(x) ((x)*(x))
#define cube(x) ((x)*(x)*(x))
const ld PI=3.141592653589793238462643383279;
const ll INF=1000000000000000000LL;
string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string abc = "abcdefghijklmnopqrstuvwxyz";
#define next_p next_permutation
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}



int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  
  ll n;cin >> n;
  ll ans=0;
  prep(i,1,n+1) {
    ll x=i;
    string s=to_string(x);
    bool f=false;
    rep(j,si(s)) if(s[j]=='8') f=true;
    if(f) ans++;
  }
  cout<<ans<<endl;
}