P11724

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
const int maxn = 300 + 100;
int n, k, ans, tmp;
int num[maxn][maxn];
set<int> st;
const int dir[4][2] = {
    { 0, 0 }, { 0, 1 }, { 1, 0 }, { 1, 1 }
};

bool in(int x, int y) {
    return x >= 1 && x <= n && y >= 1 && y <= n;
}

bool judge(int x, int y) {
    st.clear();
    for (int i = 0; i < 4; ++i) {
        int xx = x + dir[i][0];
        int yy = y + dir[i][1];
        if (!in(xx, yy)) {
            return false;
        }
        st.insert(num[xx][yy]);
    }
    return st.size() >= 3;
}

int cal(int x, int y) {
    int ret = 0;
    for (int i = x - 1; i <= x; ++i) {
        for (int j = y - 1; j <= y; ++j) {
            if (judge(i, j)) {
                ++ret;
            }
        }
    }
    return ret;
}

int main() {
#ifdef ExRoc
    freopen("test.txt", "r", stdin);
#endif // ExRoc
    ios::sync_with_stdio(false);

    cin >> n >> k;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            cin >> num[i][j];
        }
    }
    for (int i = 1; i < n; ++i) {
        for (int j = 1; j < n; ++j) {
            if (judge(i, j)) {
                ++ans;
            }
        }
    }
    tmp = ans;
    k = min(k, 9);
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            int a = cal(i, j);
            int tmpC = num[i][j];
            for (int c = 1; c <= k; ++c) {
                num[i][j] = c;
                int b = cal(i, j);
                ans = max(ans, tmp + b - a);
            }
            num[i][j] = tmpC;
        }
    }
    cout << ans << endl;

    return 0;
}