#include <bits/stdc++.h>

using namespace std;

#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = 1e18;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p;
int dx[4] = { 1,0, -1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
//#define mp make_pair


int main() {
  int b;
  cin >> b;
  int n = 100010;
  vi num(n);
  string d;
  cin >> d;
  rep (i, d.size()) {
    num[i] = d[d.size() - 1 - i] - '0';
  }
  //DEBUG_VEC(num);
  int ng = 0, ok = n;
  while (ng + 1 < ok) {
    int l = (ng + ok) / 2;
    vi a = num;
    rep (i, l) {
      a[i]++;
      a[i + 1] += a[i] / b;
      a[i] %= b;
    }
    bool flag = false;
    for (int i = l + 1; i < n; i++) {
      if (a[i]) {
        flag = true;
        break;
      }
    }
    if (flag) {
      ng = l;
    }
    else if (a[l] > l) {
      ng = l;
    }
    else {
      if (a[l] != l) {
        ok = l;
      }
      else {
        bool flag = true;
        rep (i, l) {
          if (a[i]) flag = false;
        }
        if (flag) {
          ok = l;
        }
        else {
          ng = l;
        }
      }
    }
  }
  //DEBUG(ng);
  int l = ng;
  rep (i, l) {
    num[i]++;
    num[i + 1] += num[i] / b;
    num[i] %= b;
  }
  for (int i = n - 1; i >= l + 1; i--) {
    num[i - 1] += b * num[i];
    num[i] = 0;
  }
  num[l] -= l;
  //DEBUG_VEC(num);
  string s;
  int m;
  if (ng == 0) {
    cout << num[0] << endl;
    return 0;
  }
  while (l >= 0) {
    m = num[l] / (ng + 1);
    num[l] %= (ng + 1);
    if (l == ng) {
      s.push_back(m + '1');
    }
    else {
      s.push_back(m + '0');
    }
    if (l != 0) { 
      num[l - 1] += num[l] * b;
    }
    l--;
  }
  //DEBUG_VEC(num);
  //DEBUG(s);
  if (num[0] == 0) {
    cout << (m + b - 1) % b << endl;
  }
  else {
    cout << s[num[0] - 1] << endl;
  }
  
}