#include <bits/stdc++.h>

using namespace std;
using i64 = long long;

void solve() {
    string s; cin >> s;
    int n = s.size();
    int k; cin >> k;

    vector<int> f (10);
    for (char c: s) ++f[c - '0'];


    string ans = "";
    int cf = 0, tf = n; //cf is the current frequency run, tf is the total frequenct left to allocate
    while (tf) {
        for (int d = 9; d >= 0; --d) {
            if (!f[d]) continue;
            --f[d]; //all results are calculated AFTER placing the digit 'd',  ill remove it later if doesnt satisfy
            --tf;

            int m = -1; //max elmnt in remaining digits
            int a = -1; //its freq
            for (int j = 0; j < 10; ++j) {
                if (f[j] >= a) {
                    m = j;
                    a = f[j];
                }
            }
            int currt = cf;
            if (ans.size() > 0 and ans.back() - '0' == d) ++cf;
            else cf = 1;
            int b = (d == m ? cf : 0);
            int c = tf - a;

            if (cf > k) { //cant place
                ++f[d];
                ++tf;
                cf = currt;
            } else if (a <= k * (c + 1) - b) { //can place as usual
                ans += '0' + d;
                break;
            } else if (d == m) {// if d == m then we have no noice but to remove a few of these digits from our remaining digits and place d
                ans += '0' + d;
                f[m] -= a - k * (c + 1) + b;
                tf -= a - k * (c + 1) + b;
                break;
            } else {
                ++f[d];
                ++tf;
                cf = currt;
            }
        }
    }
    int t = ans.find_first_not_of('0');
    if (t == -1) cout << "0\n";
    else cout << ans.substr(t) << '\n';
}

signed main()
{
    ios::sync_with_stdio(false); cin.tie(nullptr);
    solve();
    return 0;
}