#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for (int i=0; i<(n); ++i)
#define RREP(i, n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i, a, n) for (int i=(a); i<(n); ++i)
#define RFOR(i, a, n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()

#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<<endl;

template<class T>
ostream &operator<<(ostream &os, const vector <T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T, class U>
ostream &operator<<(ostream &os, const pair <T, U> &p) {
    return os << "(" << p.first << " " << p.second << ")";
}

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vi>;
using vvll = vector<vll>;

const ll MOD = 1e9 + 7;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
const ld eps = 1e-9;

template<typename T>
struct edge {
    int src, to;
    T cost;
};

template<typename T>
using Graph = vector<vector<edge<T>>>;

using State = string::const_iterator;


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    // ifstream in("in.txt");
    // cin.rdbuf(in.rdbuf());

    for (;;) {
        int N, C; cin >> N >> C;
        if (N == 0) break;
        map<P, int> stone;
        map<P, vector<P>> G;
        REP(i, N) {
            REP(j, i+1) {
                int s;
                cin >> s;
                stone[{i, j}] = s;
                if (i+1 < N) {
                    G[{i, j}].emplace_back(i+1, j);
                    G[{i+1, j}].emplace_back(i, j);
                    G[{i, j}].emplace_back(i+1, j+1);
                    G[{i+1, j+1}].emplace_back(i, j);
                }
                if (j+1 < i+1) {
                    G[{i, j}].emplace_back(i, j+1);
                    G[{i, j+1}].emplace_back(i, j);
                }
            }
        }

        int ans = -INF;
        REP(i, N) {
            REP(j, i+1) {
                if (stone[{i, j}] != 0) continue;
                stone[{i, j}] = C;

                map<P, bool> alive;
                function<void(int,int,int)> dfs = [&](int y, int x, int s) {
                    if (alive[{y, x}]) return;
                    alive[{y, x}] = 1;
                    for (auto p : G[{y, x}]) {
                        if (stone[p] == s) dfs(p.first, p.second, s);
                    }
                };
                REP(y, N) {
                    REP(x, y+1) {
                        if (stone[{y, x}] != 0) continue;
                        for (auto p : G[{y, x}]) {
                            if (stone[p] != 0) dfs(p.first, p.second, stone[p]);
                        }
                    }
                }

                int score = 0;
                for (auto tp : stone) {
                    if (alive[tp.first]) continue;
                    if (tp.second == C) --score;
                    else if (tp.second != 0) ++score;
                }

                chmax(ans, score);

                stone[{i, j}] = 0;
            }
        }
        cout << ans << endl;

    }

    return 0;
}




Measured memory_bytes: 3120