180331_12100_2048(easy)

	//https://www.acmicpc.net/problem/12100 #include <iostream>
	using namespace std;
	#define UP 0
	#define DOWN 1
	#define LEFT 2
	#define RIGHT 3
	int mx=0;
	int N;
	int board[20][20][2];
	int cache[6][20][20];
	void solve(int dir, int depth);
	int main(){
	cin >> N;
	for(int i=0; i<N; i++)
	for(int j=0; j<N; j++){
	cin >> board[i][j][0];
	cache[0][i][j]=board[i][j][0];
	}
	for(int i=0; i<4; i++){
	solve(i, 0);
	for(int a=0; a<N; a++)
	for(int j=0; j<N; j++){
	board[a][j][0]=cache[0][a][j];
	}
	}
	cout << mx;
	}
	void solve(int dir, int depth){
	if(depth==5) {
	for(int i=0; i<N; i++){
	for(int j=0; j<N; j++){
	if(board[i][j][0]>mx)
	mx=board[i][j][0];
	}
	}
	return;
	}
	if(dir==UP){
	for(int i=0; i<N; i++){
	for(int j=0; j<N; j++){
	if(board[i][j][0]==0) continue;
	for(int k=i-1; k>=0; k--){
	if(board[k][j][0]==0) {
	board[k][j][0]=board[k+1][j][0];
	board[k+1][j][0]=board[k+1][j][1]=0;
	}
	else if(board[k][j][0]==board[k+1][j][0] && !board[k][j][1] && !board[k+1][j][1]){
	board[k][j][0]*=2;
	board[k+1][j][0]=0;
	board[k][j][1]=1;
	}
	}
	}
	}
	}
	if(dir==DOWN){
	for(int i=N-1; i>=0; i--){
	for(int j=N-1; j>=0; j--){
	if(board[i][j][0]==0) continue;
	for(int k=i+1; k<N; k++){
	if(board[k][j][0]==0) {
	board[k][j][0]=board[k-1][j][0];
	board[k-1][j][0]=board[k-1][j][1]=0;
	}
	else if(board[k][j][0]==board[k-1][j][0] && !board[k][j][1] && !board[k-1][j][1]){
	board[k][j][0]*=2;
	board[k-1][j][0]=0;
	board[k][j][1]=1;
	}
	}
	}
	}
	}
	if(dir==LEFT){
	for(int i=0; i<N; i++){
	for(int j=0; j<N; j++){
	if(board[i][j][0]==0) continue;
	for(int k=j-1; k>=0; k--){
	if(board[i][k][0]==0) {
	board[i][k][0]=board[i][k+1][0];
	board[i][k+1][0]=board[i][k+1][1]=0;
	}
	else if(board[i][k][0]==board[i][k+1][0] && !board[i][k][1] && !board[i][k+1][1]){
	board[i][k][0]*=2;
	board[i][k+1][0]=0;
	board[i][k][1]=1;
	}
	}
	}
	}
	}
	if(dir==RIGHT){
	for(int i=0; i<N; i++){
	for(int j=N-1; j>=0; j--){
	if(board[i][j][0]==0) continue;
	for(int k=j+1; k<N; k++){
	if(board[i][k][0]==0) {
	board[i][k][0]=board[i][k-1][0];
	board[i][k-1][0]=board[i][k-1][1]=0;
	}
	else if(board[i][k][0]==board[i][k-1][0] && !board[i][k][1] && !board[i][k-1][1]){
	board[i][k][0]*=2;
	board[i][k-1][0]=0;
	board[i][k][1]=1;
	}
	}
	}
	}
	}
	for(int i=0; i<N; i++){
	for(int j=0; j<N; j++){
	cache[depth+1][i][j]=board[i][j][0];
	board[i][j][1]=0;
	}
	}
	for(int i=0; i<4; i++){
	solve(i, depth+1);
	for(int j=0; j<N; j++){
	for(int k=0; k<N; k++){
	board[j][k][0]=cache[depth+1][j][k];
	}
	}
	}
	}