#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

int power(i64 a, i64 b) {
    i64 res = 1;
    for (; b; b /= 2, a = 1LL * a * a) {
        if (b % 2) {
            res = 1LL * res * a;
        }
    }
    return res;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    i64 n, k;
    std::cin >> n >> k;

    std::vector<int> f;
    while (n) {
        f.push_back(n % 10);
        n /= 10;
    }
    std::reverse(f.begin(), f.end());

    std::vector<i64> nums, ans;
    auto dfs = [&](auto&& self, int dep, i64 cur) -> void {
        if (dep == f.size()) {
            ans.push_back(cur);
            return ;
        }
        for (int i = 0; i <= f[dep]; i++) {
            self(self, dep + 1, cur * 10 + i);
        }           
    };

    dfs(dfs, 0, 0);
    std::sort(ans.begin(), ans.end());
    // for (i64 x : ans) std::cout << x << " ";

    std::cout << ans[--k] << '\n';

    return 0;
}