#include <bits/stdc++.h>   using namespace std;   double pd[40][40][300];   int n, K;   int r[40];   int go(int a, int i, int j) {     if (a < i || a > j) return a;     return j - (a - i);   }   double solve(int a, int b, int k) {     if (k == 0) return b < a;     double& ret = pd[a][b][k];     if (ret > -0.5) return ret;     ret = 0;     double mul = 1. / ((double)((n * (n + 1)) / 2));     for (int i = 0; i < n; i++)       for (int j = i; j < n; j++) {         int aa = go(a, i, j);         int bb = go(b, i, j);         ret += mul * solve(aa, bb, k - 1);       }     return ret;   }   int main() {     cin >> n >> K;     memset(pd, -1, sizeof pd);     for (int i = 0; i < n; i++) {       int x;       cin >> x;       r[x] = i;     }     double ans = 0;     for (int i = 1; i <= n; i++)       for (int j = i + 1; j <= n; j++) {         ans += solve(r[i], r[j], K);       }     printf( %.15f n , ans);     return 0;   }   