#include <iostream>
#include <math.h>
#include <algorithm>

using  namespace std;

int len[10];


int resi(int n, int b, int e, int k) {
    if (k == 0) {
        return pow(e, 2) - pow(b, 2);
    }
    int a = INT_MAX, c = INT_MAX;
    if (len[e] <= k) {
        int temp2 = e;
        temp2--;
        while (len[temp2] == 0) {
            temp2--;
        }
        a = resi( n, b, temp2, k - len[e]);
    }
    if (len[b] <= k) {
        int temp2 = b;
        temp2++;
        while (len[temp2] == 0) {
            temp2++;
        }
        c = resi( n, temp2, e, k - len[b]);
    }
    if (a == INT_MAX && c == INT_MAX) {
        k = 0;
        return resi( n, b, e, 0);
    }

    return min(a, c);
}

int main() {
    int  n, k;
    cin >> n >> k;
    for (int i = 0; i < 10; i++) {
        len[i] = 0;
    }
    for (int i = 0; i < n; i++) {
        int temp;
        cin >> temp;
        len[temp]++;
    }
    int mali, veliki;
    for (int i = 0; i < 10; i++) {
        if (len[i] != 0) {
            mali = i;
            break;
        }
    }
    for (int i = 9; i >= 0; i--) {
        if (len[i] != 0) {
            veliki = i;
            break;
        }
    }
    int maxlen = len[0];
    for (int i = 1; i < 10; i++) {
        if (maxlen < len[i]) {
            maxlen = len[i];
        }
    }
    if (n - maxlen <= k) {
        cout << 0;
    }
    else {
        cout << resi(n, mali, veliki, k);
    }
}