[1992번] 쿼드트리

//분할정복
#include 
#include 
using namespace std;
int N;
char map[65][65];
string ans[1000];

int main() {
	cin >> N;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			cin >> map[i][j];
		}
	}
	//먼저 N/2개. 4개가 될 때까지..
	for (int i = 0; i < N; i+2) {
		for (int j = 0; j < N; j+2) {
			if (map[i][j] == map[i][j + 1] == map[i+1][j] == map[i+1][j+1]) {
				ans[i] = map[i][j];
			}
			else {
				ans[i] = map[i][j] + map[i][j + 1] + map[i + 1][j] + map[i + 1][j + 1];
			}
		}
	}
	for (int i = 0; i < N; i + 2) {
		cout << ans[i];
	}
	return 0;
}