#if __has_include("../library/Basic/Debug.hpp")

#include "../library/Basic/Debug.hpp"

#else

/* ----- Header Files ----- */
// IO
#include <cstdio>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm
#include <algorithm>
#include <cmath>
#include <numeric>

// container
#include <vector>
#include <string>
#include <tuple>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>

// others
#include <random>
#include <limits>
#include <functional>
#include <ctime>
#include <cassert>
#include <cstdint>


/* ----- Type Alias ----- */
using Bool = bool;
using Int = long long int;
using Real = long double;
using Char = char;
using String = std::string;
template <class... Ts>
using Tuple = std::tuple<Ts...>;

template <class T>
using Vector = std::vector<T>;
template <class T>
using Matrix = Vector<Vector<T>>;
template <class T>
using Queue = std::queue<T>;
template <class T>
using Stack = std::stack<T>;
template <class T>
using Deque = std::deque<T>;

template <class T>
using MaxHeap = std::priority_queue<T>;
template <class T>
using MinHeap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template <class T>
using Set = std::set<T>;
template <class T, class U>
using Map = std::map<T, U>;

template <class T, class... Us>
using Func = std::function<T(Us...)>;

template <class T>
T genv(T v) { return v; }

template <class T, class... Ts>
auto genv(size_t l, Ts... ts) {
    return Vector<decltype(genv<T>(ts...))>(l, genv<T>(ts...));
}

template <class Cost = Int>
struct Edge {
    Int src, dst;
    Cost cost;
    Edge(Int src = -1, Int dst = -1, Cost cost = 1)
        : src(src), dst(dst), cost(cost){};

    bool operator<(const Edge<Cost>& e) const { return this->cost < e.cost; }
    bool operator>(const Edge<Cost>& e) const { return this->cost > e.cost; }
};

template <class Cost = Int>
using Edges = Vector<Edge<Cost>>;
template <class Cost = Int>
using Graph = Vector<Vector<Edge<Cost>>>;

#endif

/* ----- Misc ----- */
void fastio() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
}

struct Fout {
    Int precision;
    Fout(Int precision) : precision(precision) {}
};
std::ostream& operator<<(std::ostream& os, const Fout& fio) {
    os << std::fixed << std::setprecision(fio.precision);
    return os;
}


/* ----- Constants ----- */
constexpr Int INF = std::numeric_limits<Int>::max() / 3;
// constexpr Int MOD = 1000000007;
// constexpr Real PI = acos(-1);
// constexpr Real EPS = 1e-10;
// std::mt19937 mt(int(std::time(nullptr)));

const Vector<Int> dx{-1, -1, 0, 0, 1, 1}, dy{-1, 0, -1, 1, 0, 1};

Bool solve() {
    Int n, c;
    std::cin >> n >> c;
    if (n == 0) return false;

    Vector<Vector<Int>> s(n);
    for (Int i = 0; i < n; ++i) {
        s[i].resize(i + 1);
        for (auto& x : s[i]) std::cin >> x;
    }

    Int ans = -INF;
    for (Int sx = 0; sx < n; ++sx) {
        for (Int sy = 0; sy <= sx; ++sy) {
            if (s[sx][sy] != 0) continue;

            auto t = s;
            t[sx][sy] = c;

            Queue<Tuple<Int, Int>> que;
            for (Int x = 0; x < n; ++x) {
                for (Int y = 0; y <= x; ++y) {
                    if (t[x][y] == 0) que.emplace(x, y);
                }
            }

            Vector<Vector<Int>> elim(n);
            for (Int i = 0; i < n; ++i) {
                elim[i].assign(i + 1, true);
            }

            while (!que.empty()) {
                Int x, y;
                std::tie(x, y) = que.front();
                que.pop();
                elim[x][y] = false;

                for (Int i = 0; i < 6; ++i) {
                    Int nx = x + dx[i], ny = y + dy[i];
                    if (nx < 0 || n <= nx || ny < 0 || nx < ny ||
                        !elim[nx][ny] ||
                        (t[x][y] != 0 && t[nx][ny] != t[x][y])) continue;
                    que.emplace(nx, ny);
                }
            }

            Int score = 0;
            for (Int x = 0; x < n; ++x) {
                for (Int y = 0; y <= x; ++y) {
                    if (elim[x][y]) {
                        score += (t[x][y] == c ? -1 : 1);
                    }
                }
            }

            ans = std::max(ans, score);
        }
    }

    std::cout << ans << std::endl;
    return true;
}

int main() {
    while (solve()) {}
    return 0;
}



Measured memory_bytes: 3148