#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int FFTMOD = 119 << 23 | 1;
const int INF = (int)1e9 + 23111992;
const long long LINF = (long long)1e18 + 23111992;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
inline int chkmin(T& a, const T& val) {
  return val < a ? a = val, 1 : 0;
}
template <class T>
inline int chkmax(T& a, const T& val) {
  return a < val ? a = val, 1 : 0;
}
inline unsigned long long isqrt(unsigned long long k) {
  unsigned long long r = sqrt(k) + 1;
  while (r * r > k) r--;
  return r;
}
inline long long icbrt(long long k) {
  long long r = cbrt(k) + 1;
  while (r * r * r > k) r--;
  return r;
}
inline void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
inline void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
inline int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
inline int sign(long double x) { return x < -EPS ? -1 : x > +EPS; }
inline int sign(long double x, long double y) { return sign(x - y); }
mt19937 mt(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int mrand() { return abs((int)mt()); }
struct SuffixArray {
  static const int maxn = 1e5 + 5;
  static const char sep = '$';
  int n;
  char s[maxn];
  int sa[maxn], ra[2][maxn];
  int lcp[maxn];
  void build(char* t) {
    strcpy(s, t), n = strlen(s);
    for (int i = 0; i < n; i++) {
      sa[i] = i, ra[0][i] = 0, ra[1][i] = s[i] + 1;
    }
    for (int d = 1; radixsort(); d <<= 1) {
      for (int i = 0; i < n; i++) {
        if (i + d < n) {
          ra[1][i] = ra[0][i + d] + 1;
        } else {
          ra[1][i] = 0;
        }
      }
    }
    buildlcp();
  }
  int radixsort() {
    static int p[maxn];
    static int tmpsa[maxn];
    static int tmpra[maxn];
    int mx = max(256, n) + 1;
    for (int step = 1; step >= 0; step--) {
      fill_n(p, mx, 0);
      for (int i = 0; i < n; i++) {
        p[ra[step][i] + 1]++;
        tmpsa[i] = sa[i];
      }
      partial_sum(p, p + mx, p);
      for (int i = 0; i < n; i++) {
        sa[p[ra[step][tmpsa[i]]]++] = tmpsa[i];
      }
    }
    int ptr = 0;
    tmpra[sa[0]] = ptr;
    for (int i = 1; i < n; i++) {
      int u = sa[i - 1];
      int v = sa[i];
      if (ra[0][u] < ra[0][v] || ra[1][u] < ra[1][v]) {
        ptr++;
      }
      tmpra[v] = ptr;
    }
    for (int i = 0; i < n; i++) ra[0][i] = tmpra[i];
    return ptr < n - 1;
  }
  void buildlcp() {
    for (int i = 0, k = 0; i < n; i++) {
      if (!ra[0][i])
        lcp[ra[0][i]] = 0;
      else {
        for (int j = sa[ra[0][i] - 1]; s[i + k] == s[j + k] && s[i + k] != sep;
             k++)
          ;
        lcp[ra[0][i]] = k;
        k = max(k - 1, 0);
      }
    }
  }
} sa;
void solve() {
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  auto join = [&](string s) {
    string t = s;
    reverse((t).begin(), (t).end());
    return s + t;
  };
  auto ff = [&](int d) {
    string t = s;
    reverse((t).begin(), (t).end());
    string res = t.substr(0, d);
    res = join(s);
    res += t;
    return res;
  };
  if (k == 2) {
    string res = s;
    for (int d = (0); d < (n); ++d) {
      string t = join(s);
      t = t.substr(d, n);
      t = join(t);
      sa.build((char*)t.data());
      pair<int, int> mn = make_pair(INF, INF);
      for (int i = (0); i < (n + 1); ++i) {
        chkmin(mn, make_pair(sa.ra[0][i], i));
      }
      chkmin(res, t.substr(mn.second, n));
    }
    cout << res << "\n";
  }
  auto func = [&](string s, int d) {
    s = join(s);
    s = s.substr(d, n);
    if (1 < k) {
      for (int i = (1); i < (min(k - 1, 15)); ++i) {
        s = join(s);
        int ptr = n;
        while (ptr + 1 < n + n && s[ptr + 1] == s[n - 1]) ptr++;
        s = s.substr(ptr - n + 1, n);
      }
      s = join(s);
      int ptr = n - 1;
      while (0 < ptr && s[ptr - 1] == s[n]) ptr--;
      s = s.substr(ptr, n);
    }
    return s;
  };
  string res = s;
  for (int d = (0); d < (n); ++d) {
    chkmin(res, func(s, d));
  }
  cout << res << "\n";
}
int main(int argc, char* argv[]) {
  ios_base::sync_with_stdio(0), cin.tie(0);
  if (argc > 1) {
    assert(freopen(argv[1], "r", stdin));
  }
  if (argc > 2) {
    assert(freopen(argv[2], "wb", stdout));
  }
  solve();
  cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
  return 0;
}
