/*

Author: Haze

2024/3/17

*/

#include <bits/stdc++.h>

#define irep(i, l, r) for(int i = (l); i <= (r); ++ i)
#define drep(i, r, l) for(int i = (r); i >= (l); -- i)
#define IOS ios::sync_with_stdio(false), cin.tie(nullptr);
using namespace std;
typedef long long ll;

inline ll read() {
    ll s = 0;
    bool fl = false;
    char ch = (char) getchar();
    while (!isdigit(ch)) {
        if (ch == '-')fl = true;
        ch = (char) getchar();
    }
    while (isdigit(ch)) {
        s = s * 10 + (ch ^ 48);
        ch = (char) getchar();
    }
    return fl ? -s : s;
}

constexpr int P = 1E9;
struct BigInt {
    std::vector<int> v;
};

void add(BigInt &a, const BigInt &b){
    a.v.resize(std::max(a.v.size(), b.v.size()) + 1);
    for (int i = 0; i < b.v.size(); i++) {
        a.v[i] += b.v[i];
        if(a.v[i] >= 10)a.v[i] -= 10, a.v[i + 1] ++;
    }
    while (a.v.back() == 0) {
        a.v.pop_back();
    }
}

bool operator<(const BigInt &a, const BigInt &b) {
    if (a.v.size() != b.v.size()) {
        return a.v.size() < b.v.size();
    }
    for (int i = int(a.v.size()) - 1; i >= 0; i--) {
        if (a.v[i] != b.v[i]) {
            return a.v[i] < b.v[i];
        }
    }
    return false;
}

void print(const BigInt &a) {
    const auto &v = a.v;
    if (v.empty()) {
        std::cout << "0\n";
        return;
    }
    std::cout << v.back();
    for (int i = int(v.size()) - 2; i >= 0; i--) {
        cout << v[i];
    }
    std::cout << "\n";
}

const int mod = 1000000000 + 7;
const int itinf = 1000000999;
const ll llinf = 2e18;
const int N = 500099;

void solve() {
    int n, k;
    vector<int> del(20);
    cin >> n >> k;
    string s;
    cin >> s;
    ++k;
    reverse(s.begin(), s.end());
    BigInt ANS;
    bool fl = false;
    function<void(int)> dfs = [&](int x) {
        if (x == k) {
            if ((n - accumulate(del.begin(), del.end(), 0)) % k == 0) {
                vector<int> dig(k);
                int D = (n - accumulate(del.begin(), del.end(), 0)) / k;
                irep(i, 0, k - 1) {
                    dig[i] = D + del[i];
                    if (dig[i] == 0)return;
                }
                BigInt A;
                int p = 0;
                irep(i, 0, k - 1) {
                    BigInt B;
                    B.v.resize(dig[i]);
                    int tot = 0;
                    while (p < n && dig[i]) {
                        B.v[tot++] = s[p] - '0';
                        ++p;
                        --dig[i];
                    }
                    add(A,B);
                    if(fl && A.v.size() > ANS.v.size())return;
                }
                if (!fl)fl = true, ANS = A;
                else if (A < ANS)ANS = A;
            }
            return;
        }
        del[x] = -1;
        dfs(x + 1);
        del[x] = 0;
        dfs(x + 1);
        del[x] = 1;
        dfs(x + 1);
    };
    dfs(0);
    print(ANS);
}

int main() {
    IOS
    int T;

    cin >> T;
    while (T--) {
        solve();
    }
    return 0;
}