#include <bits/stdc++.h>

using namespace std;
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
constexpr int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, -1, 0, 1, 1, -1, -1, 1};

template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec){os << "["; for (const auto &v : vec) {os << v << ","; } os << "]"; return os; }
template <typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &p) {os << "(" << p.first << ", " << p.second << ")"; return os;}

ll f(ll c) {
    ll now = 1;
    ll n = 1;
    ll ret = 0;
    while(now <= c) {
        ll d = min(c + 1, now * 10) - min(c, now);
        
        ret += n * d;
        now *= 10;
        n++;
    }    
    return ret;
}

void solve() {
    ll D;
    cin >> D;

    ll ng = 0, ok = 1e17;
    while(ok - ng > 1) {
        ll c = (ok + ng) / 2;
        if (f(c) >= D) {
            ok = c;
        } else {
            ng = c;
        }
    }
    
    cout << to_string(ok)[D - f(ng) - 1] << endl;
    
}

int main() {
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    cout.setf(ios::fixed);
    cout.precision(16);
    solve();
    return 0;
}