#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define PA pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
//#include<boost/multiprecision/cpp_int.hpp>
//namespace mp=boost::multiprecision;
//using Bint=mp::cpp_int;
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
template<class T>void print(vector<T>A){REP(i,A.size()){if(i)cout<<" ";cout<<A[i];}cout<<endl;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
//using mint=modint1000000007;
using mint=modint998244353;
//const ll mod=1000000007;
const ll mod=998244353;
//using mint=modint;
vector<ll>Q={1,0,0,0,1,0,1,0,2,1};
vector<ll>ten(19,1);
ll solve(ll N){
  if(!N)return 0;
  string S=to_string(N);
  ll M=sz(S),res=0;
  FOR(i,1,M){
    res+=5*ten[i-1];
    if(i>1)res+=54*(i-1)*ten[i-2];
  }
  FOR(j,1,S[0]-'0'){
    res+=Q[j]*ten[M-1];
    res+=ten[M-1]/5*3*(M-1);
  }
  N-=ten[M-1]*(S[0]-'0');
  res+=Q[S[0]-'0']*(N+1);
  res+=M-1;
  FOR(i,1,M-1){
    if(ten[i]<=N)res+=(M-1-i)*9*ten[i-1];
    else{
        res+=(M-1-i)*(N-ten[i-1]+1);
        break;
    }
  }
  return res+solve(N);
}
int main(){
  REP(i,18)ten[i+1]=ten[i]*10;
  ll K;cin>>K;
  ll l=1,r=1e17;
  while(l!=r){
    ll m=(l+r)/2,t=solve(m);
    if(t>=K)r=m;else l=m+1;
  }
  if(solve(l)!=K)l=-1;
  cout<<l<<endl;
  return 0;
}