#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
using VS = vector<string>;
template<class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i,a,n) for(int (i)=(a);(i)<(n);++(i))
#define eFOR(i,a,n) for(int (i)=(a);(i)<=(n);++(i))
#define rFOR(i,a,n) for(int (i)=(n)-1;(i)>=(a);--(i))
#define erFOR(i,a,n) for(int (i)=(n);(i)>=(a);--(i))
#define each(i, a) for(auto &i : a)
#define SORT(i) sort((i).begin(),(i).end())
#define rSORT(i,a) sort((i).begin(),(i).end(),(a))
#define all(i) (i).begin(),(i).end()
#define out(y,x) ((y) < 0 || h <= (y) || (x) < 0 || w <= (x))
#define line cout << "-----------------------------\n" 
#define ENDL(i,n) ((i) == (n) - 1 ? "\n" : " ")
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10;
constexpr ld pi = 3.1415926535897932;
template<class T>inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; }return false; }
template<class T>inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; }return false; }
inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }
template<class T>inline istream& operator>>(istream& is, vector<T>& v) { for (auto& a : v)is >> a; return is; }
template<class T, class U>inline istream& operator>>(istream& is, pair<T, U>& p) { is >> p.first >> p.second; return is; }
template<class T>inline vector<T> vec(size_t a) { return vector<T>(a); }
template<class T>inline vector<T> defvec(T def, size_t a) { return vector<T>(a, def); }
template<class T, class... Ts>inline auto vec(size_t a, Ts... ts) { return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...)); }
template<class T, class... Ts>inline auto defvec(T def, size_t a, Ts... ts) { return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...)); }
inline void print() { cout << "\n"; }
template<class T, class... Ts>inline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); }
template<class T>inline void print(const vector<T>& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); }
template<class T>inline void print(const vector<vector<T>>& v) { for (auto& a : v)print(a); }

int main() {
    init();

    int n, k; cin >> n >> k;
    k = min(k - 1, 20);
    string s; cin >> s;
    string u = s;
    reverse(all(u));
    u = s + u;

    char p = *min_element(all(s));
    eFOR(i, 1, n) {
        string t = u.substr(i, n);
        if (0 < k) {
            FOR(c, 0, k - 1) {
                string y = t;
                reverse(all(y));
                t += y;
                int idx = -1, cnt = 0, cur_idx = 0, cur_cnt = 0;
                rFOR(j, 0, n * 2) {
                    if (t[j] == p) {
                        if (cur_cnt == 0)cur_idx = j;
                        ++cur_cnt;
                    }
                    else {
                        if (chmax(cnt, cur_cnt))idx = cur_idx;
                        cur_cnt = 0;
                    }
                }
                if (chmax(cnt, cur_cnt))idx = cur_idx;
                t = t.substr(idx - n + 1, n);
                if (cnt >= n)break;
            }
            {
                string y = t;
                reverse(all(y));
                t += y;
                int idx = -1, cnt = 0, cur_idx = 0, cur_cnt = 0;
                FOR(j, 0, n * 2) {
                    if (t[j] == p) {
                        if (cur_cnt == 0)cur_idx = j;
                        ++cur_cnt;
                    }
                    else {
                        if (chmax(cnt, cur_cnt))idx = cur_idx;
                        cur_cnt = 0;
                    }
                }
                if (chmax(cnt, cur_cnt))idx = cur_idx;
                t = t.substr(idx, n);
            }
        }
        chmin(s, t);
    }
    print(s);
}


Measured memory_bytes: 384