#define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#include <bits/stdc++.h>
using namespace std;
#define CRP(t, x) const t &x
#define OPX(op, t, x) operator op(CRP(t, x))
#define OPL(t, x) bool OPX(<, t, x) const
#define FIL(x, v) memset(x, v, sizeof(x))
#define CLR(x) FIL(x, 0)
#define NE1(x) FIL(x, -1)
#define INF(x) FIL(x, 0x3f)
#ifndef _DEBUG
#define _DEBUG 0
#endif // !_DEBUG
#define IFD if (_DEBUG)
typedef int64_t ll, i64;
typedef uint64_t ull, u64;
template <typename T>
using enable_if_arithmetic = typename enable_if<is_arithmetic<T>::value>::type;
template <typename T>
using enable_if_integral = typename enable_if<is_integral<T>::value>::type;
inline char getchar(int)
{
    static char buf[64 << 20], *S = buf, *T = buf;
    if (S == T) T = fread(S = buf, 1, 64 << 20, stdin) + S;
    return S == T ? EOF : *S++;
}
template <typename T, typename = enable_if_integral<T>>
inline bool read(T &x)
{
    int ch = x = 0;
    while (!isdigit(ch = getchar()))
        if (ch == EOF) return false;
    for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0';
    return true;
}
template <typename T, typename... Args, typename = enable_if_integral<T>>
inline bool read(T &x, Args &... args) { return read(x) && read(args...); }
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
ll fpow(ll a, ll b, ll m)
{
    ll r = 1;
    for (; b; b >>= 1, a = a * a % m)
        if (b & 1) r = r * a % m;
    return r;
}
constexpr double eps = 1e-8;
inline int sgn(double x) { return x > eps ? 1 : x < -eps ? -1 : 0; }
const int N = 2050;
ll a[N];
int vis[N];
struct pa
{
    int i, j;
    ll v;
    OPL(pa, rhs)
    {
        if (v > rhs.v) return true;
        if (v < rhs.v) return false;
        if (i > rhs.i) return true;
        if (i < rhs.i) return false;
        return j > rhs.j;
    }
};
ll sq(ll x) { return x * x; }
int main()
{
    for (int n, k, t = 1; read(n, k); t++)
    {
        for (int i = 0; i < n; i++) read(a[i]);
        sort(a, a + n);
        priority_queue<pa> H;
        // for (int i = 0; i < n; i++)
        //     for (int j = 0; j < i; j++)
        //         H.push({i, j, sq(a[i] - a[j])});
        for (int i = 1; i < n; i++)
            H.push({i - 1, i, sq(a[i - 1] - a[i])});
        ll ans = 0;
        for (; k && !H.empty(); H.pop())
        {
            auto x = H.top();
            if (vis[x.i] == t || vis[x.j] == t) continue;
            ans += x.v;
            vis[x.i] = vis[x.j] = t;
            k--;
        }
        printf("%lld\n", ans);
    }
    return 0;
}