#include <iostream>
#include <algorithm>
#include <cstring>
#include <set>

using namespace std;

struct Pos {
  int x, y;
  Pos(){}
  Pos(int xx, int yy) : x(xx), y(yy) {}
  bool operator <(const Pos& b) const {
    if(x != b.x)
      return x < b.x;
    return y < b.y;
  }
};

int n, c;
int data[12][12];
inline int& Data(const Pos& p) { return data[p.x][p.y]; }
int adjx[] = {-1, 0, -1, 1, 0, 1};
int adjy[] = {-1, -1, 0, 0, 1, 1};

int Count() {
  set<Pos> up;
  bool check[12][12];
  memset(check, 0, sizeof(check));
  for(int i = 0; i < 12; ++i)
    for(int j = 0; j < 12; ++j)
      if(data[i][j] == 0)
	up.insert(Pos(i, j));
  while(!up.empty()) {
    Pos p = *up.begin();
    up.erase(up.begin());
    if(Data(p) < 0 || check[p.x][p.y])
      continue;
    check[p.x][p.y] = true;
    for(int i = 0; i < 6; ++i) {
      Pos q(p.x + adjx[i], p.y + adjy[i]);
      if(Data(p) == 0 || Data(p) == Data(q))
	up.insert(q);
    }
  }
  int cnt = 0;
  for(int i = 0; i < 12; ++i)
    for(int j = 0; j < 12; ++j) {
      if(!check[i][j]) {
	if(data[i][j] == c)
	  --cnt;
	else if(data[i][j] > 0)
	  ++cnt;
      }
    }
  //cout << cnt << endl;
  return cnt;
}

int main() {
  while(cin >> n >> c && n) {
    int init[12][12];
    memset(init, -1, sizeof(init));
    for(int i = 1; i <= n; ++i)
      for(int j = 1; j <= i; ++j) {
	cin >> init[i][j];
      }
    int ans = -10000000;
    //cout << "--" << endl;
    for(int i = 1; i <= n; ++i)
      for(int j = 1; j <= i; ++j)
	if(init[i][j] == 0) {
	  memcpy(data, init, sizeof(init));
	  data[i][j] = c;
	  ans = max(ans, Count());
	}
    if(ans == -10000000)
      ans = 0;
    cout << ans << endl;
    //cout << "--" << endl;
  }
}