#include <iostream>
#include <fstream>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <queue>
#include <string>
#define max(a,b) (a>b?a:b)
#define min(a,b) (a<b?a:b)
#define fori(n) for (int i = 0; i < n; i++) 
#define forj(n) for (int j = 0; j < n; j++)

using namespace std;

char getWinner(string lines[3]) {
	for (int r = 0; r < 3; r++) {
		if (lines[r][0] == lines[r][1] && lines[r][0] == lines[r][2]) {
			if (lines[r][0] != '.') return lines[r][0];
		}
	}
	for (int c = 0; c < 3; c++) {
		if (lines[0][c] == lines[1][c] && lines[0][c] == lines[2][c]) {
			if (lines[0][c] != '.') return lines[0][c];
		}
	}
	if (lines[0][0] == lines[1][1] && lines[0][0] == lines[2][2]) 
		if (lines[0][0] != '.') return lines[0][0];
	if (lines[2][0] == lines[1][1] && lines[2][0] == lines[0][2]) 
		if (lines[2][0] != '.') return lines[2][0];
	return '.';
}

int main() {
	ifstream in ("DATA2.txt");	// IS THIS THE RIGHT NUMBER?
	ofstream out ("OUT2.txt");  // IS THIS THE RIGHT NUMBER?


	for (int Z = 0; Z < 5; Z++) {
		string lines[3];
		for (int l = 0; l < 3; l++) {
			getline(in,lines[l]);
		}	

		out << getWinner(lines) << endl;	
	}
	return 0;
}