const int LG = 21;
const int FN = 400005;
const long long MOD = 1e9 + 7;
const long long INF = 1e9;
const long long INFLL = 1e18;

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <cmath>
#include <time.h>
#include <unordered_set>
#include <bitset>
#include <deque>

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<ll> vi;

#define forn(i, n) for (int (i) = 0; (i) != (n); (i)++)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define popcount(x) __builtin_popcount(x)
#define popcountll(x) __builtin_popcountll(x)
#define fi first
#define se second
#define re return
#define uniq(x) sort(all(x)); (x).resize(unique(all(x)) - (x).begin())

#ifdef LOCAL
#define dbg(x) cerr << __LINE__ << " " << #x << " " << x << endl
#define ln cerr << __LINE__ << endl
#else
#define dbg(x) void(0)
#define ln void(0)
#endif // LOCAL

int cx[4] = {-1, 0, 1, 0};
int cy[4] = {0, -1, 0, 1};

ll inq(ll x, ll y)
{
    if (!y) re 1 % MOD;
    ll l = inq(x, y / 2);
    if (y % 2) re l * l % MOD * x % MOD;
    re l * l % MOD;
}

ll rev(ll x)
{
    return inq(x, MOD - 2);
}

bool __precomputed_combinatorics = 0;
vector<ll> __fact, __ufact, __rev;

void __precompute_combinatorics()
{
    __precomputed_combinatorics = 1;
    __fact.resize(FN);
    __ufact.resize(FN);
    __rev.resize(FN);
    __rev[1] = 1;
    for (int i = 2; i < FN; i++) __rev[i] = MOD - __rev[MOD % i] * (MOD / i) % MOD;
    __fact[0] = 1, __ufact[0] = 1;
    for (int i = 1; i < FN; i++) __fact[i] = __fact[i - 1] * i % MOD, __ufact[i] = __ufact[i - 1] * __rev[i] % MOD;
}

ll fact(int x)
{
    if (!__precomputed_combinatorics) __precompute_combinatorics();
    return __fact[x];
}

ll cnk(int n, int k)
{
    if (!__precomputed_combinatorics) __precompute_combinatorics();
    return __fact[n] * __ufact[n - k] % MOD * __ufact[k] % MOD;
}

const int N = 100500;

int n;
vector<pair<int, ll> > graph[N];
int sz[N];

void dfs(int v, int p)
{
    sz[v] = 1;
    for (auto u : graph[v]) if (u.first != p)
    {
        dfs(u.first, v);
        sz[v] += sz[u.first];
    }
}

ll dist[N];

void dfs2(int v, int p)
{
    for (auto u : graph[v]) if (u.first != p)
    {
        dist[u.first] = dist[v] + u.second;
        dfs2(u.first, v);
    }
}

string find_the_best(string t)
{
    int n = t.size() / 2;
    string res = "";
    forn(i, n) res += t[i];
    for (int i = 1; i <= n; i++)
    {
        int c = -1;
        for (int j = 0; j < n; j++)
        {
            if (t[i + j] == res[j])
            {
                continue;
            }
            if (t[i + j] < res[j])
            {
                c = 1;
                break;
            }
            else
            {
                break;
            }
        }
        if (c == 1)
        {
            res = "";
            forn(j, n) res += t[i + j];
        }
    }
    return res;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    ll n, k;
    cin >> n >> k;
    string s;
    cin >> s;
    if (k >= 14)
    {
        sort(all(s));
        forn(i, n) cout << s[0];
        return 0;
    }
    while (k)
    {
        string g = s;
        reverse(all(g));
        g = s + g;
        if (k == 1)
        {
            s = find_the_best(g);
        }
        else
        {
            reverse(all(g));
            s = find_the_best(g);
            reverse(all(s));
        }
        k--;
    }
    cout << s;
}

/* Note:
Check constants at the beginning of the code.
    N is set to 4e5 but be careful in problems with large constant factor.
    Setting N in every problem is more effective.
Check corner cases.
    N = 1
No def int long long for now.
Add something here.
*/


Measured memory_bytes: 2688