#include <bits/stdc++.h>
const int mx = 2e5 + 10;
using namespace std;
long double dp[222][33][33];
int a[33];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 1; i <= k; i++) {
    for (int l = 0; l < n; l++)
      for (int r = l + 1; r < n; r++) {
        long double sum = 0;
        for (int x = 0; x < n; x++)
          for (int y = x; y < n; y++) {
            int p1 = l, p2 = r;
            if (x <= l && l <= y) p1 = y - (l - x);
            if (x <= r && r <= y) p2 = y - (r - x);
            if (p1 > p2)
              sum += 1 - dp[i - 1][p2][p1];
            else
              sum += dp[i - 1][p1][p2];
          }
        dp[i][l][r] = sum / (n * (n + 1) / 2);
      }
  }
  long double ans = 0;
  for (int i = 0; i < n; i++)
    for (int j = i + 1; j < n; j++) {
      if (a[i] < a[j])
        ans += dp[k][i][j];
      else
        ans += 1 - dp[k][i][j];
    }
  cout << fixed << setprecision(9) << ans << endl;
  return 0;
}
