#include <iostream>
#include <vector>
#include <string>
#include <cmath>
using namespace std;

vector<int> make_dist(const string& src_string) {
    vector<int> dist(10, 0);
    for (auto c : src_string) {
        int i = c - '0';
        dist.at(i)++;
    }
    return dist;
}

string make_up_number(vector<int> dist, int nearest, int lucky_id) {
    string up_string;
    if (nearest >= 0) {
        while (dist.at(lucky_id) > 0) {
            dist.at(lucky_id)--;
            up_string.push_back(char(lucky_id + '0'));
        }
        while (dist.at(nearest) > 0) {
            dist.at(nearest)--;
            up_string.push_back(char(nearest + '0'));
        }
    }

    for (int i = 0; i < dist.size(); i++) {
        while (dist.at(i) > 0) {
            up_string.push_back(char(i + '0'));
            dist.at(i)--;
        }
    }
    return up_string;
}

string make_low_number(vector<int> dist, int nearest, int lucky_id) {
    string down_string;
    if (nearest < dist.size()) {
        while (dist.at(lucky_id) > 0) {
            dist.at(lucky_id)--;
            down_string.push_back(char(lucky_id + '0'));
        }
        while (dist.at(nearest) > 0) {
            dist.at(nearest)--;
            down_string.push_back(char(nearest + '0'));
        }
    }

    for (int i = dist.size() - 1; i >= 0; i--) {
        while (dist.at(i) > 0) {
            down_string.push_back(char(i + '0'));
            dist.at(i)--;
        }
    }
    return down_string;
}

string find_near_lucky_num(string& _1st, string& _2nd, int lucky_num) {
    int bNum = 0;
    int sNum = 0;
    int kNum = 0;
    for (int i = 0; i < _1st.size(); i++) {
        bNum = bNum * 10 + (int)(_1st.at(i) - '0');
        sNum = sNum * 10 + (int)(_2nd.at(i) - '0');
        kNum = kNum * 10 + lucky_num;
        if ((bNum - kNum) < (kNum - sNum)) {
            return _1st;
        }
        else if ((bNum - kNum) > (kNum - sNum)) {
            return _2nd;
        }
    }
    return _1st;
}

int main()
{
    int test_num;
    cin >> test_num;
    while (test_num--) {
        string src_string;
        int lucky_id;
        cin >> src_string >> lucky_id;
        vector<int> dist = make_dist(src_string);
        int nearest_upper = -1;
        for (int i = lucky_id + 1; i < 10; i++) {
            if (dist.at(i)) {
                nearest_upper = i;
                break;
            }
        }
        int nearest_lower = 10;
        for (int i = lucky_id - 1; i >= 0; i--) {
            if (dist.at(i)) {
                nearest_lower = i;
                break;
            }
        }

        if (nearest_upper == -1 && nearest_lower == 10) {
            cout << src_string << endl;
        }
        else if (nearest_upper == -1) {
            cout << make_low_number(dist, nearest_lower, lucky_id) << endl;
        }
        else if (nearest_lower == 10) {
            cout << make_up_number(dist, nearest_upper, lucky_id) << endl;
        }
        else {
            auto up_num = make_up_number(dist, nearest_upper, lucky_id);
            auto low_num = make_low_number(dist, nearest_lower, lucky_id);
            cout << find_near_lucky_num(up_num, low_num, lucky_id) << endl;
        }
    }
    return 0;
}



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