#include <bits/stdc++.h>

using namespace std;
typedef long long int ll;
typedef pair<int, int> ii;
#define DEBUG freopen("in.txt", "r", stdin);

struct fastio {
    fastio() {
        ios::sync_with_stdio(false);
        cout << setprecision(10) << fixed;
        cin.tie(0);
    }
};

fastio _fast_io;

const int N = 1e5 + 5;
int n, m, k;
int a[N];
ll ans;

int main() {
    cin >> n >> k;
    m = n;
    ans = LLONG_MAX;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        if (m == n && a[i] >= 0) {
            m = i;
        }
    }
    for (int i = 0; i <= min(k, m); ++i) {
        if (m + k - i - 1 >= n) continue;
        ll lv = 0;
        ll rv = 0;
        if (i)
            lv = -a[m - i];
        if (k - i)
            rv = a[m + k - i - 1];
        // cout << i << ' ' << lv << ' ' << rv << endl;
        ans = min(ans, min(lv, rv) * 2 + max(lv, rv));
    }
    cout << ans << endl;
    return 0;
}

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define each(x, y) for (auto &x : y)
#define all(a) (a).begin(), (a).end()
#define bit32(x) (1 << (x))
#define bit64(x) (1ll << (x))
#define sz(v) ((int) v.size())

using namespace std;

using i64 = long long;
using f80 = long double;
using vi32 = vector<int>;
using vi64 = vector<i64>;
using vf80 = vector<f80>;
using vstr = vector<string>;

inline void yes() { cout << "Yes" << endl; exit(0); }
inline void no() { cout << "No" << endl; exit(0); }
inline i64 gcd(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); if (a % b == 0) return b; return gcd(b, a % b); }
inline i64 lcm(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); return a / gcd(a, b) * b; }
template <typename T> class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T> class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> inline void amax(T &x, T y) { x = max(x, y); }
template <typename T> inline void amin(T &x, T y) { x = min(x, y); }
template <typename T> inline T exp(T x, i64 n, T e = 1) { T r = e; while (n > 0) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; }
template <typename T> istream& operator>>(istream &is, vector<T> &v) { each(x, v) is >> x; return is; }
template <typename T> ostream& operator<<(ostream &os, vector<T> &v) { rep(i, v.size()) { if (i) os << ' '; os << v[i]; } return os; }
void solve(); int main() { ios::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(16); solve(); return 0; }

void solve() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  using P = pair<string, string>;
  vector<map<P, int>> lst(n + 1);
  rep(i, bit32(n)) {
    int x = __builtin_popcount(i);
    string a, b;
    rep(j, n) {
      ((bit32(j) & i) ? a : b) += s[j];
    }
    lst[x][P(a, b)] += 1;
  }
  i64 ans = 0;
  rep(i, bit32(n)) {
    int x = __builtin_popcount(i);
    string a, b;
    rep(j, n) {
      ((bit32(j) & i) ? a : b) += s[n + j];
    }
    reverse(all(a));
    reverse(all(b));
    ans += lst[x][P(a, b)];
  }
  cout << ans << endl;
}